Ten One Design - T1-PGCT-302 - Pogo Connect 1 Bluetooth 4.0 Smart Pen, for iPad 3/4 Full feature set requires a compatible App. Low Energy Bluetooth 4.0. It's amazingly sensitive, with 0 grams of activation force It works at all angles It requires no calibration It provides hundreds of levels of pressure Location beacon to help keep track of your stylus Months of continuous use on one battery