IKSACE E3Z-R61 Photoelectric Beam Sensor Indoor Wall Mounted NPN (NO Or NC Switchable) Retroreflective photoelectric Sensor Proximity Switch with 2M Cable,Reflector Panel, Pack of 2 2 pieces Size:2 pieces Easy to install Expansion is

Easy to install Expansion is created by tightening a threaded bolt which draws a tapered cone expanding a sleeve against the walls of the hole

1/4-20 x 1-1/2" Hex Head Bolts

15 with 6 mm

strong grinding power

IKSACE E3Z-R61 Photoelectric Beam Sensor Indoor Wall Mounted NPN (NO Or NC Switchable) Retroreflective photoelectric Sensor Proximity Switch with 2M Cable,Reflector Panel, Pack of 2 2 pieces Size:2 pieces Easy to install Expansion isIKSACE E3Z R61 Photoelectric Beam Sensor Indoor Wall Mounted NPN (NO Or NC Switchable) Retroreflective photoelectric Sensor Proximity Switch with 2M Cable,Reflector Panel, Pack of 2 Explanation on the definition of NO, NC, NPN, PNP: NO(Normally open): the circuit is open when there is no sensing object, and the circuit is closed after sensing the objectNC(Normally closed): the circuit is closed when there is no sensing object, and the circuit is open