Sports bras are a necessary evil. I’m not the bustiest runner, but even I need a high-support bra to neutralize the laws of physics. Adding a chest strap to the mix, however, often feels like I’ve signed up to run 13 miles with a python squeezing my chest. Which is why the $149.99 Garmin HRM-Fit chest strap is a stroke of genius.

To get why the HRM-Fit is so great, you need to understand how regular chest straps fail sports bra wearers. Traditional chest straps are typically an elastic loop that wraps around your entire body with electrodes on the underside. Because the electrodes need to maintain good contact with your skin, you have to tighten the loop such that it doesn’t slip. Stick that under a medium- or high-support sports bra — which is already pretty constrictive — and it’s a bad time. Add underboob sweat to the mix, and keeping my Polar H10 clean is a whole job.

It might not seem like a huge change, but the HRM-Fit doesn’t wrap fully around your chest. Instead, there are three clips that latch onto your sports bra band. There are also two electrodes on the underside. I cannot overemphasize how enjoyable the HRM-Fit was to use because of that simple design change.

The clips make it so there’s no additional pressure. I often forgot I was even wearing it. Conversely, I’m always acutely aware of my Polar H10. Also, with the HRM-Fit, cleaning the strap is easy because underboob sweat wasn’t as much of an issue because there isn’t a ton of fabric touching my skin. I went from dreading putting on my chest strap to not minding it at all.

I’m all for a chest strap that doesn’t ask people with tatas to sacrifice any comfort, especially since chest straps help people who either can’t use smartwatches or for whom smartwatches aren’t the best option. (Have you tried putting a boxing glove over a smartwatch? Not fun.) Plus, they’re more accurate than optical heart rate sensors since they actually measure your heartbeat via electrical signals instead of light reflected off your skin. That makes them great picks for people with tattoos and more melanated skin.

That said, it’s not perfect. Because it latches onto your bra, you need the right kind of sports bra. Garmin has a little guide, but it works best if you have a bra with a medium-width band. I found that if the band was too narrow, the HRM-Fit wouldn’t lay flat. That ruled out a few of my favorite sports bras. Another bummer is that it’s not recommended with front-zip sports bras. It can also be tricky if you use sports bras with underwires. I was lucky that the HRM-Fit mostly worked with the majority of my sports bras, especially since replacing them would be so damn expensive. But depending on your sports bra preferences, the HRM-Fit may not be compatible.

I also wish the HRM-Fit were easier to use outside of Garmin’s platform. It’s super simple if you’re using it with a Garmin watch. But it’s not quite as easy to view real-time data if you’d rather use the HRM-Fit with a third-party smartwatch or on its own. Say you go for a run without a Garmin watch. The strap will record metrics like steps, calories, intensity minutes, and heart rate — but it won’t record that data as part of a run. Conversely, Polar’s chest straps work with the separate Polar Beat app that can record timed activities, even if you don’t have a Polar watch.

This is less of a problem if you plan to use this with gym equipment or fitness apps that support third-party accessories. It has Bluetooth and ANT Plus, so you can view data on a machine in real time. Meanwhile, if you pair to connected machines like Peloton Bikes and fitness apps, you’ll at least get to see your HRM-Fit recorded data within that app’s workout summary. In the Garmin Connect app, you can only view it as part of your overall daily data unless you’re using it with another Garmin device.

I also don’t love that, at $150, this is much more expensive than the Polar H10 or Wahoo’s various Tickr chest straps. Those you can easily find for under $100, especially during the holidays. It’s the pink tax. Not only do you have to buy a sports bra but you also have to pay more to use a chest strap that works comfortably with them. But even with all my quibbles, I’m stoked that the HRM-Fit exists. Finally, someone in the fitness tech space has acknowledged that chest straps can — and should — be designed differently for people who wear bras.