T yoke OD: 110mm ID : 37.95mm hole 20, Effective height :27mm Thickness: 6mm Surface treatment: electrophoresis(black) Washer OD: 110mm ID :40.7mm Thickness: 6mm Riveting hole:80*4 Surface treatment: electrophoresis(black) This parts can customize to fit your speaker design.discount Speaker Parts T-yoke And Washer website:http://www.chinasoundspeaker.com/speaker-parts/speaker-parts-t-yoke-and-washer/