I can't take the credit for this but when I bought pans from the Washington Ferret Shelter that had a securing system I knew it was good. Thanks to Kevin Farlee who got the idea from someone else. With a standard cat litter pan cut off the top lip of the pan with a razor knife. Get a strip of lath or a heavy duty paint stir paddle or a piece of millwork called "stop." Whatever, cut it about 2 inches shorter than the width of the pan. Secure it to the backside of the pan at a height that will work with your type of cage. Put the screws on the inside so they screw through the plastic and into the wood. Then drill two more holes on the outside of the back into the wood and screw in two screw eyes. You should first do a dry run and mark the position with a Sharpie. For SuperPet cages it is important to place the wood and hardware quite high so it is above the edge of the tray. Then place the pan in place with the screw eyes sticking out to the outside and slide a 1/4 or 5/16 dowel through the eyes. That's it. Easy to remove, fairly ferret resistant. You will need the piece of wood, a small drill bit (7/64) and two hex-head sheet metal screws, 6 x 3/8. You can buy those in a little packet at Home Depot of Lowe's or at any hardware store, and also get a packet of #10 screw eyes and a dowel, 1/4 or 5/16. Cut that in half. That is all you need, presuming you have a basic drill and saw. The hex head screws are easy to set in using the 1/4 inch opening of one of the cheap multi-bit screwdrivers. I have done this on most of the pans in my shelter and it really has solved the moving problem. After a while the determined ones give up trying. Carol -- Carol J. Owens Ferret Friends, Inc. Tucson AZ [Good idea using hex-head screws since some ferrets are less likely to have that type of screwdriver! BIG] [Posted in FML 8026]