Description Centra Block Club Vertical and horizontal adjustment of the sightline – Base height of 10 mm – Vertical adjustment in 4 mm increments up to the final height of 22 mm – One maximum horizontal offset out to 4 mm. – Rear-sight-dovetail can shift 25mm Replacement Clamping Block and Screw for Centra Block Club Centra/Mec item # 19915903, 19915901, 19915902 OE SKU # 18746, 15416, 15417
