I had them on my rear jacks and used BAL X chocks as well. Got tired of messing with them. Just took them off and tossed them this Summer. They were pretty well rusted up from non use. Quit using the X Chocks as well. Now I just use large yellow chocks by my wheels. I can't say that I notice much if any difference. Maybe I'm just getting used to it...
2015 Chev Silverado 3500 dually D/A
2016 Cedar Creek 36CK
B&W Patriot 18K, Trail-Aire pinbox,
Level up, dual panes & all that stuff...