OK here it is No filler! No polly! No foam! No Shopping! No Spring! No more making plugs 100% reusable! How dose it work? the bridge is in the resivor of juice and takes it when it needs it with out any flooding.. What you need Place the cap that comes with your carts firmliy on the cart till you see a black outline of the cart threw the cap Cut along the black line You should end up with somthing like this.. Now you need to make a decission either cut a x or * in the center of the rubber plug or punch a 2mm hole in the center both work really well! When using the X or star it will open up when the atty's bridge makes contact with it.. Now cut a straw to 15mm give or take 1mm I just eyeball it.. so you can make a shelf for the plug to rest on.. Insert the straw all the way to the bottom and fill with juice to the top of the straw.. if you desire you can cut vents into the straw for more juice room up to you. Insert rubber plug down till it hits the straw ENJOY! if you get it right you will know it and will not have to make another plug again.. if you feel your atty is not getting enough juice make the X or star bigger or try the hole.. I relize this takes some skill to get it right if there is a demand for them pm me and ill make packs of 5 for small fee..