When replacing swivels you will need to determine the size and type of swivel. 6" Swivels work for seats with a 4-3/4" to 5-1/2" distance between bolts. 7" Swivels work for seats with a 5" to 5-3/4" distance between bolts. Use a Flat Swivel for Backless and Open Back seats. Use a 3° Pitched Swivel for Bucket seats. 7” Pitched Swivel with Return are also available. Keep your existing hardware, swivels do not include nuts or bolts.