HM-10 New Portable 4.0 BLE Bluetooth 4.0 Uart Transceiver Module cc2540 CC2541 Central Switching Still use Bluetooth 2.1? IF you are in need of such a 4.0 BLE Bluetooth module, MCU can be set up,also can controlled by a remote Bluetooth device for setting,can transfer data, and can remotely control 10 PIO pins,so,the best choice is HM-10/11 bluetooth module. HM-11 size is only have 2.4cm X 1.5cm . HM-11 can work with IOS, PC, Android 4.3. 1. Brand new and high quality. 2. Send and receive no bytes limit. 3. The power can be adjusted -23dbm, -6dbm, 0dbm, 6dbm, can modify through AT Command AT+POWE. 4. Long range, Open space have 100 Meters with iphone4s. 5. Low Power: Only 0.5 mA for standby, Active 8.5 mA, support auto sleep. 6. Central & Peripheral in one. 7. UUID FFE0, FFE1. 8. Support serial port update firmware (add in V508).