The STK 40 GL, formerly the CIS 40 GL[a] is a 40 mm grenade launcher, developed in the late 1980s and produced by the Singaporean defense firm CIS - Chartered Industries of Singapore (currently ST Kinetics).
The launcher is employed primarily by the Singapore Armed Forces and the police and security forces of several other countries.
[1] According to ST Kinetics Senior Engineer Felix Tsai, the STK 40 GL can be configured to be used with a buttstock or attached underneath assault rifles like the SAR-21, the M16 and HK series.
[2]