Charlie, are you asking about the wheel choc itself? What you have chosen for your item is the part number for locking the choc into the bracket. so the choc won't bounce out and you lose it going down the road.
Model QCH-SL may be added to the QCH-1, QCH-2 and QCH-32-H horizontal holders to prevent the wheel choc from sliding out of the storage bracket. May be added to any ZICO horizontal holder presently in service.
Charlie go to our web site and under vendors look for "ZICO" you will find some different size wheel choc's look there for your size you will need
Answered on 8/2/2016 by bg