Growl is a startup launching a wall-mounted fitness device that uses a combination of projectors and sensors to give you a life-size boxing coach to train with. Unlike similar interactive trainers such as the Lululemon Mirror or Tonal, the Growl encourages physical interactivity with its screen that doubles as a punching bag you can actually hit. However, just like those smart home workout machines, it’s pretty expensive, even with the hardware costs spread across a monthly subscription.

Pricing for unlimited family access is “anticipated” to start at $150 per month on a 48-month plan or $190 per month for 36 months when preorders open in April 2025. That puts the price tag at $7,200 for four years or $6,840 for three. That’s not far off from the $7,407 cost of a Peloton Tread Plus over four years, including monthly subscription fees, and as with Peloton’s hardware, you’ll own the Growl at the end of the subscription period.

By using projectors instead of LCD or OLED screens, its makers say that the Growl creates a more immersive experience without adding extra size. (Although it stays mostly out of the way, its design is described as “compact as a wall shelf.”) Your progress and other useful metrics are projected on the walls around the Growl. At the same time, its main screen, which is essentially half a punching bag that the company says offers similar resistance to the real thing, displays a life-size virtual trainer that’s more engaging.

The Growl detects when and where you’ve punched it using a series of infrared time-of-flight sensors, turning its flexible surface into a large touchscreen, while multiple cameras track your movements in 3D and provide real-time feedback using AI analysis.

You can spar with the virtual trainer as they show you where to throw punches, or you can play interactive fitness games including a title that looks like the boxing equivalent of Beat Saber that has you punching a series of targets flying toward you.

It’s not just designed to track how long you’ve worked out or how many calories you’ve burned. It can suggest how to improve your form and technique without ever having to step into a ring and risk getting punched back.