These bushings are made of chromolly and are sold INDIVIDUALLY. The tie rod over bushing (TRO) is used after you ream your knuckles to put the tie rod on top of the knuckle. It is designed to be used with the F-150 tie rod or use a TRA bushing inside the TRO and you can use the shock EB tie rod. To use this produce you will need to ream your knuckles using a 1 1/2″ of taper per foot of run tapered ream. Applications are as follows: 1. The EB tie rod to the F-150 knuckle (tie rod under). 2. The drag link to the tie rod when going tie rod over (any combo). 3. Used with the TRO bushing when going tie rod over with the F-150. knuckles and the EB tie rod. For #1 above you will need 2 TRA bushings. For #2 above you will need 1 TRA bushing. For #3 above you will need 3 TRA and 2 TRO bushings.