Be confident in your purchase, we are a Certified Algae Free Dealer, how cool is that?!? Acrylic Glass Replacement Pad Kit For all Tiger Shark Great White Cleaners. Each glass replacement pad kit contains: (1) Self-adhesive, non-toxic Velcro pads for inner assembly (2) Self-adhesive natural felt pads for outer assembly The pads should be replaced approximately every 3-6 months Monitor your pads for wear. Changing times vary depending on the amount of usage. Always remove any debris from your pads as it could scratch the glass. To replace the felt pad: 1. Pull as much of the old felt off the wood piece as possible. 2. Using a piece of 100 grit sandpaper, lay the cleaner down onto a flat surface and rub the cleaner on the sandpaper to remove the rest of the felt and adhesive. 3. Peel and stick the new felt onto the wood piece and place onto the aquarium for 6 hours to make sure the felt adheres properly. To replace the Velcro holding pad: 1. Pull the old Velcro off the inner assembly. 2. Peel and stick the new Velcro pad onto the inner assembly.