Acrylic Replacement Pad for Hammerhead/Piranha Algae Magnet For Piranha &amp; Hammerhead Float algae magnets 1 Adhesive-backed natural felt pad for protection on outer surfaces of acrylic tanks 3 9"x5" acrylic-safe inner scrubbing pads (makes 12 Hammerhead Float pads) 1 Self-adhesive, non-toxic medical grade Velcro pad for holding acrylic safe scrubbing pads on inner