The Ikan ELE-P-QRBP is a 15mm elements plus quick release base plate for DSLR camera bodies. The ELE-P-QRBP is a 15mm threaded rail system with proprietary dovetail base plate with 1/4”-20 and 3/8”-16 screw mounts. The ELE-P-QRBP was designed for small to midsized camcorders and DSLRs. To attach your camera, spin the top wheel. To attach the rail system to a tripod, spin the bottom wheel.