These J-Cup protectors are designed to protect the finish and knurling on your barbells from the metal-on-metal contact on the front lip of your J-Cups.
Sold as a pair.
The Strength Co currently makes just one variation of their J-Cup, so if yours looks like the pictures here, this design should fit.
1. Using an Allen wrench (usually 5/32" or 4mm), remove the original bottom UHMW strip.
2. Slip your new J-Cup Protector over the side of the J-Cup. You will need to spread the part apart a small amount.
3. Finish sliding it across and down onto the J-Cup.
3. Screw your original plastic over the top of the new protector. Your original screw should work.