BeaLasers Micro SEN 301 RHL (Red Line Laser):

Micro SEN 301 RHL (Red Line Laser):  650 nm (red), <1mW.  1/4″-36 fully threaded 15mm long brass tube (sensor type housing).  5mm threaded cable connector for reliable power connections. 1 meter long cable.  Detachable brass end cap / holder.  Line optic.