Universal Lug Nut Cover (PGDSF92LNT) by Phoenix USA. With Jam Nut crimped inside, 9/16" ID x 1 5/8 tall used in NSF921 & NSF941. Jam nut used in simulator kits GDSF92, NSF921, and NSF941. Nut with stainless steel cover permanantly attached. 9/16" ID, 1 5/8" tall, 30mm hex.