About this item:(Only compatible with Contactless and chip 2st generation)! The square reader dock has an anti-sleep button, and you can activate the Square Dock without having to take it out of the dock.With a USB interface, you can power the dock through USB without worrying about the safety hazards caused by too long power cables.The bottom has a non-slip silicone pad, which can effectively prevent loosening during use.The perfect counterweight, after half a year of testing, engineers finally determined the most scientific counterweight weight, which is easy to carry without affecting its functionality.