Size: The size of S is 17cm(Length)*11cm(Width) which is suitable for kids and junior. The size of M is 19cm(Length)*12.5cm(Width) which is suitable for adults. The size of L is 21cm(Length)*13.5cm(Width) which is suitable for adults who need to increase exercise Material: Consist plastic paddle and silicone straps makes the swimming hand paddle adjustable and comfortable. It has great elastic that you will not feel restraint Anti-Slip: Silicone non-slip, even in the water it will not slip and cause the fins to fall off your hand. Good fit saves you the trouble of adjusting the proper placement Unique Design: There are several drainage holes on the surface of the paddle, which can automatically adjust the drainage according to the user's strength, so that the training effect is better Other Advantages: Our swimming hand paddle is environment-friendly without any special odor and the smooth surface does not hurt handscan. It can greatly improve the speed of swimming Material: Consist plastic paddle and silicone straps makes the swimming hand paddle adjustable and comfortable. It has great elastic that you will not feel restraint. Anti-Slip: Silicone non-slip, even in the water it will not slip and cause the fins to fall off your hand. Good fit saves you the trouble of adjusting the proper placement. Unique Design: There are several drainage holes on the surface of the paddle, which can automatically adjust the drainage according to the user's strength, so that the training effect is better. Other Advantages: Our swimming hand paddle is environment-friendly without any special odor and the smooth surface does not hurt handscan. It can greatly improve the speed of swimming.