Carbon Express pin nock adapters fit all standard pin nocks. Constructed out of premium grade 6061-T6 aluminum. Fits Maxima Pro Recurve, Predator 2040-3050, Any Standard .244 ID arrows, CXL 150 (NEW .284), X-Buster 600-700, CXL 250-350, X-Buster 350-500, Line Jammer Pro and X-Jammer 27 Pro