Big Apple Rodent Cage (LARGE) 21.5" L x 15.5" W x 7-7/8" H Lids made of high quality narrow straight wire stainless steel making it both extremely durable and escape proof. The lid has a hinged water bottle divider and separate food area. Special hold down clips insert neatly into the heavy duty polypropylene plastic base which enables incredible security without sacrificing ease of access. Easy to clean, affordable and built to last for years of continuous use. Lids are made of Stainless Steel with separate feeding and watering wells. Tubs are made of Polypropylene with the following characteristics: Extension At Break 50%; Pull-Out Strength MPa 23; Degree Of Hardness 85; Density (kg/m3) 905; AutoClave Max Rec Temp 130 C, 266 F; Melt Flow g/10min 29; Arm Beam Strength I/M 65; Density 0.90-0.91