5V Indicator Light LED One 1 Channel Relay Module For Arduino ARM PIC AVR DSP Brand new and high quality. The 8550 transistor drive, drive ability. High quality 5v relay. Have relay status indicator led. Relay control interface by single chip IO. Low level suction close, high level release. Easy to use, simple 3 line structure. Power LED(Green), relay status indicator LED(Red). Size: 4.4cm x 2.6cm - 1.7inch x 1inch.