Hosyond 4Pack 4 Channel DC 5V Relay Module with Optocoupler Relay Board for Arduino Raspberry Pi MEGA2560 industrial It also stabilizes the pH

It also stabilizes the pH

Made primarily of a non-conductive thermoplastic along with steel tightening screw and toggle grip

Muli-Color

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Hosyond 4Pack 4 Channel DC 5V Relay Module with Optocoupler Relay Board for Arduino Raspberry Pi MEGA2560 industrial It also stabilizes the pHHosyond 4Pack 4 Channel DC 5V Relay Module with Optocoupler Relay Board for Arduino Raspberry Pi MEGA2560 Module parameters: Size: 71. 5mm(L)52. 7mm(W)18. 5(H)mm Single weight: 56g PCB color: blue There are 4 fixing screw holes around the board, the hole diameter is 3. 1mm, which is convenient for installation and fixing High quality relays. A common end, a normally open end, and a normally closed end. Optocoupler isolation, good anti interference.