The Samson Hannibal Rail variant for the T-1 pattern footprint was based on a request from a state law enforcement agency. They wanted a direct mount solution that allows the end user to mount any RDS (Red Dot Sight) utilizing the Aimpoint T-1 footprint directly to the Hannibal Rail, putting the optic much closer to the bore-line than other mounts. The integrated Picatinny rail on top of the Hannibal Rail is perfect for mounting any additional accessory your heart desires, and gives your rifle a more tactical look. The included 2" Picatinny rail and QD swivel mount can be attached to the side of the Hannibal Rail for even more accessory mounting options. Just some of the optics using the T1/T2/H1/H2 footprint:Aimpoint T1/T2/H1/H2Holosun 403, 503, 515, and 530Sig Sauer Romeo 4, 5, & Romeo-MSRPrimary Arms SLX Advanced Rotary Knob, SLX MD-20Bushnell TRS-125Vortex Crossfire, Sparc SolarSightmark (multiple models)Swampfox LiberatorFor any other models, check with your sight manufacturer ...