... 1.LED vivid screen 2.seven adjustable massage intensities 3.safety guarantee PJM 921S handheld massager Feature: 1. Dual massage ... . 6. Overcharge power protection is designed to ensure your safety. In case of overcharge power, the motor stops automatically and immediately, and ... another technique for your safety. The controller's LCD keeps flashing Err2 and the motor stops in case that the voltage is ...