The Sure Grip 50 Magnetic Powerhead Holder provides a new way of attaching power heads to your aquarium. Using the Sure Grip, certain Maxi-Jet, Tunze Stream or Seio Super Flow powerheads can be placed anywhere on the wall of a glass or acrylic aquarium. The Sure Grip 50 comes complete with two magnetic housings, eight sticky-backed rubber feet and four different plastic brackets. Time to get rid of those prone-to-fail suction cups.Algae Free Sure Grip 50 Magnetic Powerhead Holder is compatible with the following pumps and aquarium thicknesses:Seio Super Flow M620, Seio Super Flow M820, acrylic or glass 1/2" or lessTunze Stream All Models, acrylic or glass 3/8" or less (we do not carry the Tunze pumps)Maxi-Jet 400, Maxi-Jet 600, Maxi-Jet 900, Maxi-Jet 1200, acrylic or glass 1/2" or less