The strong sticky gel base is added to the suction cup to provide stronger hold.The suction cup will perform in cold or hot environment. These do stick and hold wonderfully on a smooth surface (like a car or glass),however, any plastic surface suction cup will not stick if there is any texture to the surface whatsoever. Each anchor hold up to about 20lbs, Long Lasting hold,and it will not come off until you remove it.Provide very strong grips on smooth surface. Includes versatile wide gate spring hooks and attaches via heavy-duty webbing.These suction cups stick to smooth fiberglass surfaces like glass, boats, cars and campers. Perfect for When you are out traveling, you can connect two cars to hang your clothes, tent, canopy, and you can hang anything, which is convenient to use and carry.It works on most non-porous smooth surfaces.The sucker/suction cup hooks will hold its place as long as needed.