module relay 4ch 5v arduino

Description Product description: 1, the module complies with international safety standards, the control area load area the isolation groove; 2, the genuine relay Songle; 3, have the power & relay action instructions, pull bright disconnect does not shine; 4, when a signal in the signal input terminal, the common terminal and the normally start conduction; 5, microcontroller development board can be 2 as a module that can be 2 as a home appliance control; 6, the control of the DC or AC signal, can control the 220 v AC load; 7, there is a normally open and a normally closed contact. 8, blue KF301 terminals to the line of control is more work.