1、Kit Contents: This relay module kit is composed of a 4 channel infrared receiver relay driver board and a remote 4CH infrared transceiver infrared remote control switch. 2、Internal Battery: The remote controller included in the relay module set comes with an internal battery, so you don't need to spend any effort to pick one, and the remote controller consists of multiple buttons, which can extend more working modes. 3、PCB and ABS Material: This relay module set is made of PCB and ABS material, which has good strength and can do long term use under normal use. 4、Compact Size: The compact size of the relay module set means that it is easy to carry around, very easy to install, and can be easily stored when not needed, without taking up too much space. 5、Superb Craftsmanship: Our relay module set is made of superb craftsmanship and a versatile design, making you very comfortable in the process of using it. Item Type: 4 Channel Relay Module Receiver Set Material: PCB, ABS Remote Controller Power Supply: Requires CR2025 button cell x 1, battery capacity 50mah (remote controller shipped with internal battery) 1 x Relay Module 1 x Remote Controller