This is an easy way of fitting your sulledge hose to your van,instead of pushing your hose onto your van fitting very hard to do when cold and stiff,I have glued two fittings onto the van outlet so I can screw the sulledge fitting on instead of pushing it on,it is nothing new but maybe someone hasen,t seen this idea,the big green shed has all the bits.
My mate bought those for his van. He has since seen the clip on ones that he has ordered for me with the larger drain hose. (sold with my previous van) He is now trying to find his receipt to exchange for the clip on ones.