Yet another brilliant idea from John Dadd of the CMCA Bushwackers Chapter in Victoria. On most 5th wheelers there is usually no parking brake, as most have electric brakes and you can't have an override coupling on a "gooseneck" coupling. The fact that the jacks are on the ground is relied upon to stop the unit rolling. John's simple solution of two blocks held together with a cheap turnbuckle works just brilliantly. You do not need a spanner and John's wife, Jan actually fits these each time they are on a soft site. It takes about 30 seconds to fit one. This sytem would also work on any motorhome with a tag axle such as many of the Matildas.