I have 2 brand new WHOOP 4.0 activity trackers for sale. Asking $100 a piece or both for $150 WHOOP is a 24/7 digital fitness and health coach that provides actionable sleep, recovery and training insights in real-time. WHOOP came to Aruliden with advanced technology that could better track key fitness metrics to take the guesswork out of training. Since 2013 we've worked with the WHOOP founding team to package this ground-breaking technology into a streamlined wearable, worn 24/7, that's changed how people live and train