Hejnar Photo precision aluminum extension spacer block for Metabones Gen 2, 3, and 4 Canon EF to Sony E-mount lens adapters providing extended tripod and L-bracket clearance. 50mm high-precision macro focusing rail with 100 TPI adjusting screw drive and indexable 4-position quick release clamp. 25mm micrometer adjusting macro rail featuring a genuine Mitutoyo precision head, Delrin slider block, and 4-position quick release clamp.