Gehmann Multi-height Sight Base 844 Gehmann multi-height sight base sets For use on all standard rails Offers several height capabilities (from 13mm up to 28mm) - in combination with packing discs supplied (4 x 1mm, 4 x 2mm, 4 x 4mm, 4 x 8mm) Includes matching length allen screws to suit your chosen height Lateral shift across of 5mm Laser engraved indications Spring-loaded, stable clamps Finished in an attractive alloy and black combination