HCP9813SET2 Aftermarket brake caliper retainer plate pin rubber DUST BOOTS, used on either side of the joining pin that retains the caliper body to the retainer plate. This specially formed accordian bellows boot is usually disintegrated on original calipers, and interferes or prevents the caliper from "floating" properly against the retainer plate. Use 2 per caliper on all XJ550, XJ750 Seca, and XJ1100 (front calipers only) models. Set of two boots does one caliper:
$ 14.95
Contact Len at Xj4ever.com as this is an older post that I am quoting from but he is the guy I had make the stainless lines for these bikes and he has a great selection of parts. Worth an email to him to see I am sure.