No, the Streamlight TLR-7A Flex LED Tactical Weapon Light is too large to fit the CR920 accessory rail. You would need the Glock compatible TLR-7 Sub, which can be found by using the link below:
https://www.opticsplanet.com/streamlight-69428-tlr-7-laser-light-combo-handgun-glock-led-500-lumens-black-alu.html?_iv_gun-make=glock&_iv_gun-model=glock-48
The Streamlight TLR-7A Flex LED Tactical Weapon Light might fit a Shadow Systems CR920. However, I recommend using the Streamlight model at the link below.
https://www.opticsplanet.com/streamlight-69428-tlr-7-laser-light-combo-handgun-glock-led-500-lumens-black-alu.html?_iv_gun-model=glock-48-w-accessory-rail
Yes this will fit shadow systems. The guy above doesn’t know what he’s talking about. This is not the subcompact version. This will fit nicely on a Glock 17 or 19. A shadow systems firearm is basically an upgraded Glock 19. You will be fine with this light.