Size: Medium MAX / 8" x 4" Magnets: 2 pairs of waterproof N52Max neodymium magnets, recommended for 5/8" thick aquarium wall. Frags: Holds up to 27 small 1inch frags or 13 large 1.5inch frags Material: High quality crystal clear cast acrylic. Waterproof sealed, triple protected magnets. Adaptation: 1/2" frag holes fit most frag plugs, strong protected magnets hold steady on glass, acrylic and plastic containers. Designed and manufactured by reefing art aquarium. Create additional space on the aquarium wall to grow, display coral frags. Only top grade materials are used to ensure the best / strongest frag rack in the market.