The ACCU-SYNC® Flip-up Rear Sight by UTG® is designed from machined aircraft aluminum with a matte black finish. Pressing the posi-lock push button puts the spring loaded front sight into position and prevents the sight from collapsing when deployed. No tools are needed to further adjust the sight once it's been installed. To mount the sight, simply tighten the single locking torx screw in its low-profile mounting base onto your rifle's rail. The sight also has integral recoil stop for a secure zero hold and return to zero.