DB200 adjustable smart dumbbell, connected to JAXJOX ? APP via Bluetooth, provides professional fitness training courses, scientifically manage your exercise intensity, and grasp your fitness quality level, built-in 3D acceleration sensor, real-time accurate monitoring of your exercise data number, number of groups, weight, calories consumed, heart rate... The data you want is clear at a glance, ergonomic design, non-slip handle, beautiful and generous, comfortable grip, your molding tool, free weight adjustment, APP/host base free weight adjustment, you want to achieve the weight immediately.