Dump Trailer Service Contract. Here's What's in Mine!

I have ordered a dump trailer for my needs and have decided I need to upgrade to a larger truck as well. The increased costs have gotten me to decide that I will offer dump trailer services. I have been in the process of creating a contract for it and here is what I have in it.

Trailer Locks:
https://www.amazon.com/s?k=trailer+locks&linkCode=ll2&tag=agiftedcurse-20&linkId=506a9d5b36d5d395070250c9191d2bfc&language=en_US&ref_=as_li_ss_tl

Trailer Chocks:
https://www.amazon.com/s?k=trailer+chocks&linkCode=ll2&tag=agiftedcurse-20&linkId=6b5bd8ed6cc6e22578e183ece0701751&language=en_US&ref_=as_li_ss_tl

Rachette Straps:
https://www.amazon.com/s?k=rachette+straps&linkCode=ll2&tag=agiftedcurse-20&linkId=632bb23d35e6528e23bd7b2da4dcc0d5&language=en_US&ref_=as_li_ss_tl