We currently have neighboring rvers that have 2 cats. One likes to be out. They have a toy dog collar with the fastener for a leash on the cast and then have a small plastic covered wire type lead that about 8' long with the fastener for the collar on the end. One end tied/fastened around a small hook on the trailer, the other end with fastener in collar ring. Cat can wander a little, lay in the sun etc. They are always outside with it also. They also have a fabric & mesh carrier meant for 2 cats that they sometimes have the cats in at times when they are doing something (reading etc) where they may not be aware of all that's going on immediately. Seems to work real well for them.