WR PRECISION PICATINNY RIFLE SIGHT RAILS - T1x *ALL WR T1x rails have a contoured base to hug the top of the T1x receiver (ie. the T1x rail base is not flat like the T3 rail base) to ensure maximum resonance dampening between rifle and sight solution. That is why the WR product is the BEST.*ALL WR T1x pic rails come with 6-48 black high tensile Torx 15 socket mounting screws. *ALL WR T1x rails are bi-ported for LH and RH receivers... with clearing chamfers over the ejection port for finger feeding single rounds.