This 19.75 suction cup grab bar by Drive Medical is a dual rotating grab bar, allowing you the added versatility of adjusting the bars to multiple angles. It can be installed and removed without the hassle of tools or a service professional, allowing the product to be used right out of the package. The large suction cups provide an extremely strong hold. Release levels make attaching and detaching the bar a cinch. A color indicator shows you whether installation was safe secure or if you must re-affix the grab bar. The product is guaranteed to not damage your property. The suction cup is 4 in diameter and must make full contact with a smooth surface without breaking grout.