No. The Leapers UTG OP3 Micro Red Dot Sight uses the Docter/Noblex footprint, which is not compatible with the optic cut found on the Hellcat OSP. You can fit optics with the Shield RMSc footprint like the Sig Romeo Zero and Romeo Zero Elite.
No. The Leapers UTG OP3 Micro Red Dot Sight uses the Noblex footprint, which is not compatible with the optic cut found on the GX4 T.O.R.O. You can fit optics with the Shield RMSc footprint as well as the RMRcc with a plate directly from Taurus.
The Leapers UTG OP3 Micro Red Dot Sights use the Docter/Noblex footprint. The Springfield XDS MOD2 OSP has an optics cut to fit the Shield RMSc footprint, so the Leapers UTG OP3 Micro Red Dot Sights will not fit.
The Leapers UTG OP3 Micro Red Dot Sights use the Docter Footprint. The Leapers UTG OP3 Micro Red Dot Sights can be mounted to a Canik Rival using the compatible mounting plate from Canik.
The Leapers UTG OP3 Micro Red Dot Sights could be mounted on a Ruger Security 9 using a dovetail mounting plate. The Leapers UTG OP3 Micro Red Dot Sights use the Docter/Noblex footprint. So the mounting plate listed at the link below will work. You will need model number 49290.
https://www.opticsplanet.com/evolution-gun-works-vortex-viper-venom-fits-burris-fastfire-and-docter-1-811-in.html?_iv_gun-make=ruger
The Leapers UTG OP3 Micro Red Dot Sights use the C-MORE footprint. If your slide has an optics cut to fit red dots with the same footprint, then the Leapers UTG OP3 Micro Red Dot Sights should mount just fine.
The Leapers UTG OP3 Micro Red Dot Sights will mount to picatinny rail using the included mount. So yes, the Leapers UTG OP3 Micro Red Dot Sight will mount to a Citadel PAT 12 gauge using the picatinny rail on the top of the receiver.
Yes, you could mount the Leapers UTG OP3 Micro Red Dot Sights to a Sig P226 if you use the correct adapter plate. I am not sure if the slide or sights have changed on the P226 since your model has been produced. If they haven't changed then this plate here will work.
https://www.opticsplanet.com/evolution-gun-works-vortex-viper-venom-fits-burris-fastfire-and-docter-1-811-in.html?_iv_gun-make=sig-sauer-1&_iv_code=KK-RMT-VRXV-49318
You will need model number: 49318
The Leapers UTG OP3 Micro Red Dot Sights use a Docter/Noblex footprint. So it will mount on a Springfield XDS but you will need this mounting plate.
https://www.opticsplanet.com/evolution-gun-works-vortex-viper-venom-fits-burris-fastfire-and-docter-1-811-in.html?_iv_gun-make=springfield-armory&_iv_code=KK-RMT-VRXV-49323
Yes, the Leapers UTG OP3 Micro Red Dot Sight will work but you will need this adapter plate.
https://www.opticsplanet.com/evolution-gun-works-vortex-viper-venom-fits-burris-fastfire-and-docter-1-811-in.html?_iv_gun-make=glock