I bought 2 of the 6 volt battery box locks 2 years ago after I had my 6 volts stolen. The thief wasn't very nice. Cut the cables & left the battery box lids on the ground & stole the boxes. One of the boxes had my cut off switch screwed to it so the cost of that theft went even higher. I have now attached the cutoff switch to the frame so it can't be stolen again. The battery lock brackets shown in the links here have worked very well for me. I have been happy with them. I'm lucky as they are made locally so one of the RV dealers carry them.