Size: S:7*3.7*6.8cm,suitable for about 20-30cm fish tank and fish tank thickness < 5mm. Quantity:2pcs Material: Made of super strong magnet and plastic, durable and convenient. Strong absorption ability and powerful magnetic attraction. As you move the outer magnet, the inside magnet follows,cleanning the floating algae faster and easier. Floating Design : Because of powerful magnetic attraction, as you move the outer magnet, the inside magnet follows, hence cleans the glass.The internal floating avoids the brush sinking in the bottom of aquarium and makes it convenient to take it out of the tank. Multi-functions : Soft anti-slippery handle can make your hand comfortable and improve your cleaning actionwhile anti-scratch cleaning pads are highly efficient in removing algae from glass Labor saving and time saving.The upgraded Soft handle is streamlined, anti-slippery, comfortable, labor-saving and time saving. Note: Pay attention to safety when using, and be careful to clamp your hands.