Features 1、The module includes 4 channel 12V/10A relay modules and SPP‑C Bluetooth serial port slave module, which can be controlled by mobile phone APP. 2、Onboard STM8S high‑performance MCU and SPP‑C Bluetooth 2.1 slave module. 3、Can be connected continuously for 100,000 times, with diode effusion protection, and short response time. 4、Onboard Bluetooth status indicator and relay indicator, the status of the relay module is clear at a glance. 5、Reserve UART debugging interface and STM8 SWIM program download interface for easy testing and use. Specification Item Type: Relay Module Control Distance: Approx. 10meter / 32.8ft (open environment) Working Voltage: DC12V Module Size: Approx. 63 x 63mm / 2.5 x 2.5in Package List 1 x Relay Module