The 12" suction cup grab bar by Drive Medical can be installed and removed without the hassle of tools or professional installation, meaning you can use it 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.