No pic for you but use your imagination here. Have some fun with lubester. Bolt a pvc flange down inside to bottom directly under upper hole opening. Then silicone a piece of 4" pvc pipe into it that's long enough to come up to within about 2 inches of lid. Find some cushion springs from old sofa, bed, or whatever. Tie them together as one spring. Put them down into pvc tube with top of springs about 2" from lid. Now put some fuzzy animal looking toy on top of spring & jam lid down. Insert spring pin or small bolt to hold lid closed. Have friends take a look at what's in the tank! My favorite toy was a Tasmanian devil slipper, but I guess you could use a real live road kill temporarilly but don't forget that it's in there!! Enjoy.