Fits Models: Ryobi 130R and 135R electric trimmers; 700R, 710R, 720R, 740R, 750R, 970R, CS720R, SS720R, Singer GT2815, GTS2816 and GTE2818Troy-Bilt TB75SS and TB475SSYard Machines Y28 and 2800M
Specifications: OD: 1 3/4" OD 1 3/4"5/16"-18 THDPoly bagged
Additional Information: Use with 385-178 Trimmer Head 385-178 Trimmer Head