what kind of laser is this?
532nm says DPSS (Diode pumped solid state) with intracavity doubler. 

It is really two lasers, an 808nm diode laser that provides optical pump power to drive a Nd-YAG laser crystal that operates at 1064nm. Within the YAG laser cavity is a non linear element that generates the output light by frequency doubling the 1064nm radiation to get to 532nm.
I would expect the pump laser to be a few hundred mW or so to get 40mW of green.

Be careful, 40mW does not sound like much, but given the application it might have quite good beam quality (And may even be passively Q switched) in which case that is quite sufficient to cost you (or someone nearby) an eye. 
DPSS lasers also sometimes leak significant amounts of infra red along an axis that is not necessarily aligned with the main beam.