Sure Grip is a magnetic holder for powerheads, used to replace original brackets and/or suction cups. It can be placed anywhere on the wall of your glass or acrylic aquarium. This product contains 2 magnetic housings, 8 sticky-backed rubber feet and 4 different plastic brackets. Please refer to the diagrams below to ensure that you are using the correct powerhead bracket on your Sure Grip magnetic powerhead holder. Assembly Take each of the housings and place the sticky-backed rubber feet in each of the recessed holes. Press firmly for 5–10 seconds. Now take the bracket labeled for your powerhead (refer to diagrams below) and slide it on to one of the magnetic housings. This will now be the inner housing. Slide the powerhead onto that bracket. You are now ready to position the powerhead in your tank. Hold the inner housing with powerhead and position it inside the aquarium. Now slowly slide the outer housing on the outside of the aquarium adjacent to the inner housing until they engage. Warning Algae Free's Sure Grip Holders are NOT TOYS! Keep away from children! Sure Grip magnetic holders contain very strong magnets. Whenever handling these magnets, caution must be used or injuries (especially painful pinching) may occur. Keep magnetic products away from electronic equipment, other magnets, pacemakers and medical devices. Failing to do so may result in permanent damage to such devices. TUNZE STREAM—all models For the Tunze Stream you will need to use the two Tunze adaptors (not included) pictured below as well as the pictured bracket from this package.