Special design can efficiently prevent worm from escaping.Comes with strong sucker for stable and firm installation.Suitable for tortoise, lizard, frog, gecko or other small size reptiles. Material: Qualified ABS Size: 7x7x8cm Delivery Quantity:2 piece How To Installation: STEP 1 : Separate the four parts,Use water and a rag to cleanthe surface of the soft pads that come into contact with the glass,as well asthe glass,wipe it clean,be sure free of dust and other impurities. STEP 2 : Put the soft pad on the position you want to place andpress it tightly by hand. STEP 3 : Put on the hard cover and press tightly by hand. STEP 4 : Cap the nut and screw it to the tightest position.There is a knob on the front of the suction cup to release or increase thesuction on the glass. STEP 5 : Lightly press the feeder into the screw cap to completethe final installation