Replacement rear (bolt on) prop adapter for 6320 and 6330 series Himax Outrunners. Includes new fasteners to mount to Himax motor, washers and 12mm nut. For those wishing to check other brand motors for possible fit, adapter is setup for 4 each 3mm fasteners in 8mm diameter circle, fits over boss .982" (24.9mm) diameter and adaper base is recessed .132" (3.35mm) to accept boss. Shaft length is 1.45" (36.7mm) long with a diameter of 12mm. SKU Number: HC63-8