650nm red light laser module industrial laser module 5mw adjustable focal length point 2pcs (6mm) (line-2packs)

I tested it with 3.7V and with 5V. Works very nice with both voltages. You need to play with the lens on the front (screw in/out) to adjust it to a fine thin line (or wider if you like).

Focal threaded adjustment could be better with more friction

They are VERY small but quite powerful. I am using them to make a laser guided drill press and so far it is working. an old 5volt phone charger supplies power.

I purchased this laser lamp to replace a broken laser beam on my miter saw. The light worked brightly enough, but it is a diffused light. The beam is approximately one inch wide, which is too wide for a miter saw guide, as it needs a hair-thin light.

Exactly what I needed.