Whoop won't sell you the strap. There's no device price on the site, just a $199 to $359 a year membership with the hardware bundled in, because the whole business is the software layer, the recovery and strain analytics that were supposed to be too hard for anyone to rebuild. One developer rebuilt them. He reverse-engineered the strap's Bluetooth protocol, recomputed recovery, strain, HRV and sleep locally in a SQLite database on your own phone, and shipped it as a free app called NOOP. No Whoop account, no cloud, nothing leaves your device. Works with Whoop 4.0 and 5.0. Then it got worse for the model. People took the free app and started forking it. The guy above runs his own personal fork, tuned to the metrics he cares about, and AI coding tools are what made maintaining a fork of a reverse-engineered wearable app a weekend project instead of a career. Subscription hardware always rested on one assumption. The device is cheap, the software is hard, so you charge for the software forever. That held for exactly as long as software stayed hard. Whoop has over 2.5 million members. Every one of them already owns the sensor.