Yes, it will work with Steiner lasers. Here is a list of most of the lights and lasers this pressure switch is compatible with:
Lights:
Surefire M300, M300U, M300V, M600AA, M600AA-DSS, M600U, M600V, M600V-AA, M620, M620V, M720, M952, M952V, P2X-Fury, X200, X300, X300UA, X300UB
Lasers:
ATPIAL-C, CQBL-1, DBAL-A2, DBAL-A3, DBAL-D2, DBAL-I2, DIAL-100, ITAL. LA-5/5C, MAWL-DA, OTAL, AN/PEQ-15, AN/PEQ15a, AN/PEQ-16A, AN/PEQ-16B, AN/PEQ-2A, RAPTOR ES, RAPTOR Lite