Whadda Four-Channel Solid State Relay (Ssr) module can be used to quickly and efficiently switch on and off AC loads without using any moving parts (e.g. as a classic electromechanical relay). The Ssr module uses a phototriac to provide a galvanic isolation between the logical level side and the AC load side. All four channels can be turned on by providing a high logical level signal (3 - 5 V), and turned off by providing a low logical level signal (0 - 1.5 V) to its corresponding channel signal input. Please note that this module can only switch alternating current, up to a maximum of 2 A, with a maximum voltage of 240 V alternating current. Attempting to use this module to change DC power load or to exceed the specified limits may damage the module and/or your connected devices . Basic Product Information: •• Operating Instructions Language: English •• Primary Colors: Blue •• Additional Colors: Black, Blue •• Additional Detailed Colors: Light Blue •• Depth Unit: 57 mm •• Height Unit: 24 mm •• Width Unit: 55 mm •• Weight Unit: 36.8 g • Technical Data: •• Specifications Kit & Modules: Specifications Max. Load Voltage: 240 V AC Max. Load Current: 2 A Supply Voltage: 5 V DC Ssr Working Current: 12.5 Ma Ssr Trigger Voltage: 0 &ndash, 1.5 V DC Ssr Trigger Current: 2 Ma • Operational Characteristics: •• Coding Level: 2 •• Electronics Skill Level: 3 •• Mechanics Skill Level: None •• Soldering Skill Level: None