This handy exercising tool is built with high quality material. Thus, it is flexible and durable. The gripper set is specifically designed with quality silicone and flexible finger holes. It will help prevent the band from slipping off your fingers. The finger stretchers are washable and long lasting. They are also nontoxic, and free of BPA, phthalates. You can simply wash them up with water and mild soap. They do not tend to have any sort of odour or terrible smell. Hence, an ideal hand exerciser.