I bought one for my very first gecko......he has passed and i still have it but i'm not using it for my girls as it is the small one. I plan on getting the large one for the girls soon. To prevent any injury from getting stuck between the glass and the cave, i put a few bricks or rocks securly behind it so its sitting fimly up against the glass. I also make sure its sitting flat on the bottom. Sometimes the plastic trim on the tanks make this hard cause in order for the outside piece to attach the cave must be raised above the trim. I'll sit the cave on a brick above the trim to correct this.
Red 
>>I went to the petstore a few days ago and seen this magnetic rock dens. Were the rock den is on the inside and they sleep with privaicy and then the other side is magneticly on to were I can pull it off to watch them sleep. I thought that they looked stupid, but my mom talked me into one. It actually is quite neat and they love it! My concern is, is this magnetic bond between the glass okay for them with them in it?? Is this a good item?
-----
Crested Gecko Zeek:1.0
LEOS: Boo: 1.0 normal , Bronx & Nala: 1.1 blizzard,
Lily: 0.1 patternless, Abby: 0.1 albino, Zoe: 0.1 reduced pattern, Dot: 0.1 hypo
Chip: 1.0 papillion (small dog)