I had about 5-7 pounds on top of mine. I had a locking screen top, but it didnt fit right so only one end locked, and the other end wouldn't. My 5 month old bp pushed his way out of his tank one night and found him in the bathroom a day later. I learned that they are a lot stronger than I gave them credit for. I think VooDooDoc's looks pretty good IMO. I went to a reptile expo three days later and got one that the top slides into a rail from the side with two pins that lock it in place and i love it so far. Its escape proof "I think".