In general, the clip needs a spring to provide the clamping force, but the metal spring will pose a threat to organisms in the marine tank. We innovatively use high-elastic nylon (environmentally friendly and odorless) to provide the clamping force for the clip, without using any metal parts, forever No rust, please rest assured to use. Only the real RuFeB magnets dare to say that, the maximum support is 19mm, a wide adaptable range of 5-19MM, and there is no doubt that the strong suction force does not need to consider whether the carrying capacity is sufficient. The design of concave and convex lines at the clamping place firmly clamps the target, so that the normal bite of the fish cannot tear the seaweed from the clamp. Only the real RuFeB magnet can say this.