This is a Steel Trailer Spindle Nut for use with a 13/16" Spindle Nut Retainer Cage. The inner diameter of this Spindle Nut Measures 13/16", and the Thread Count is 13/16" x 20. This style of Trailer Spindle Nut is used with D Style Spindles, which use a D Washer and a retainer clip or cage, not with a cotter pin.Features:- 13/16" - 20 Trailer Spindle Nut- for use on 13/16" 'D' Style Trailer Spindles- Not for use with cotter pins