Circular Slim v2024 - the world's most discreet alarm clock!

The latest version of Circular SLIM. What's new since the last version? What do I like and what don't I like?

LORDoftheSMARTRINGS

14 Aug 2024 — 8 min read

I was one of those early adopters who put some of my faith and money into a "vibrating ring" 2 years ago. A lot has changed since then and many competing rings have been made. I've also written a number of articles and reviews about the Circular Ring - you can find them at #circular

A few weeks ago I received a version that can be called the "Circular Slim version 2024". I have already tested and reviewed the Circular Slim (2023):

I have to say that I was quite surprised when the Circular team contacted me to say that they had a new version available. In this article, we'll take a look at what's new - both in terms of HW and SW.
Let's have a taste:

Incorporated community feedback,
a unique in-app chart
and new metrics.

So let's do it 💥

💍PRO and 💍 SLIM

Circular currently has three versions of the rings in its portfolio:

PRO - thicker, with vibration and button,
SLIM - thinner, with vibration and haptic control,
SLIM Light - thinner, without vibration.

⚙️ Hardware

So what's happened since March, when I reviewed the Circular Slim, which we can now call "version 2023"?

Logo ⚪

The first thing you'll notice when looking at the 2023 and 2024 versions is definitely the logo. The white logo was a disappointment to many users. In fact, it's so positive that Circular took this feedback into account and corrected their mistake (in the v2023 renders, the logo was embossed and not white ink...).

The body of the ring

I've been testing different versions of Circular for a couple of times now, and you can see the progress. This is both good and bad news. You can see that the materials are constantly being improved, which unfortunately means that those who received the ring in the past have a less well-made version.

With the v2024 in particular I can see that:

Integrity - the ring is very smooth and solid.
A certain transparency - If you look closely, you can see some components slightly visible through the casing, which I find quite interesting.
🌊 Water resistence - previous specs talked about IPX8, now Circular talks about IP68, specifically that you can submerge the ring in 5 metres of water for a maximum of 30 minutes. It is not recommended for use in salt water.
✂️ Durability - the manufacturer says that there have also been advances in scratch resistance. I cannot confirm or deny this at this time. The ring has had a few scratches, but I don't usually keep these rings.

Circular Slim v2023 vs. v2044 & Oura ring Gen3

Weight and thickness

Nothing has changed here, Circular Slim still holds the title of lightest ring.
It also boasts the marketing title of thinnest, but with a 'but'. Namely, it is the thinnest in its thinnest part.

Charger and charging pins

Charging pins were a no-go for a long time. They were big and sometimes very uncomfortable. I took a photo one morning after a night out with the first version of the Circular Pro:

I add two things - the pins are still present, but they are smaller and smoother now. And second, a lot depends on how the ring fits. One of the general pitfalls of a smart ring is choosing the right size. That is, comfortable to wear (not too tight) and of good quality (not too loose).

A good argument for the pins is that they "bite" into the skin, preventing the ring from twisting on the finger. The "bubbles" on the Oura and RingConn work in a similar way, though obviously not as aggressively.

As for the charger, it's still a minimalist pendant with a USB-C male.

Battery

The battery has remained the same, and the battery life is still not great, around 2-3 days. This is in performance mode, when the ring tracks more frequently and provides more detailed information, such as sleep detail. If you want to save battery and don't need more detailed information (and more frequent heart rate readings), Eco mode (5-6 days) is better.

This article provides a comparison of battery life in the context of other rings:

Sensors

For the sake of order, which will come as no surprise to regular readers of this blog, I will mention the classic sensors. These include a 3-axis accelerometer, a temperature sensor and a PPG sensor to measure blood pulse and related metrics.

Somewhat uncharacteristically (at least compared to other rings), the sensors are positioned 'sideways'. They don't point directly at the bottom of your finger. I wondered why...

📱 Software

I've talked about the Circular app (both iOS and Android) many times in my previous articles and videos. And here you can see the progress and actually continuous development - which is clearly documented in the Release Notes.

Currently I am referring to version: 20.0.3.

I'm not going to describe the application environment again here, I will mainly talk about the new features. However, for the sake of clarity, I am releasing an updated application roadmap. I published the original version in the v2023 review.

🧭Navigation

Within the individual ⭕Circles, two have been added since the last check:

🏃‍♂️ Sports Sessions
📈 Advanced Analysis

We will look at both circles separately.

🏃‍♂️ Sport Sessions

Sport Sessions allows you to track individual workouts/activities. I validated the accuracy of the measurements in a 7 ring comparison and compared to the others, it was actually not bad.

There are a variety of sport activity types to choose from and, now standard, a GPS route is included if you have your phone with you and give the app permissions.

📈 Advanced Analytics

This app contains quite a unique thing in the smart ring field, it's an interesting interactive chart. You can view up to about 10 metrics in a daily and monthly view.

Something similar can be found as part of the Oura ring - but in the Oura Cloud web interface.

Reviews & my experience

Quite frankly, I don't wear the Circular as my primary smart ring. I wear it occasionally to try out new features. Well, I have to say that the most useful feature I've come to love it for is the discreet alarm.

I usually share a bed with my wife and there are sometimes other people/kids in the room at night and I like to get up early. Ideally, I wake up alone and don't want to wake anyone up. Over the past few weeks, the Circular Ring has been helping me towards that early wake-up. As I mentioned in my last review, the ring has a 'smart alarm' option.

This option is designed to ensure that the ring wakes you up (by vibrating) at the ideal time for your sleep light-phase within a pre-defined time window. I was a bit sceptical about this at first, mainly because the sleep phase or hypnogram is the worst in the long term with the Circular. However, they have now implemented a new version and there has been some progress (I plan to test more in the future).

At the same time, I was wondering how the light phase wake-up works, since the sleep phases are all calculated retrospectively, only when synchronising with the phone...

Takže údajně porovná dříve získané parametry s "raw daty" během aktuálního spánku

I find it very difficult to judge the accuracy of the light sleep phase. I often wake up a little before the ring starts to vibrate. Here's an example of a night when the Circular hit the light phase, even according to Oura:

I still expect more from KIRI+, which is an AI assistant. I expect it to give better and more personalized recommendations.

Conclusion

If I had to define the pros and cons of the Circular SLIM, they would be very similar to those in the (last) review.

If you are tempted by the Circular Slim ring, you can (and should):

1) Use my link for an 8% discount ;)

CIRCULAR 8% DISCOUNT CODE

2) Read the various forums - especially reddit. You will always find negative cries of "scam". Again, I say it's not a scam. In my opinion, most of these cries are related to an unsatisfactory refund. That's obviously worrying. Personally, I had a problem with a 2023 ring and after a very long and tedious process with customer support, I got a new ring. But I suppose it was because they knew I would be reviewing it...

I share this because it's important to choose carefully where you invest your money. I have been transparent about my experiences.

Circular, at least in my bubble, is quite active in marketing. They've also started putting out some YouTube videos. They appreciate more openness, but I feel they could have put more emphasis on professionalism... or the taste of the arrangements:

And in the last video they compare the Circular to other rings - the clones (AKA Smart Ring Copies) and the AIZO ring. That's a bit disappointing for me, I think they should be targeting completely different brands...