Flexible, Safe and Durable Construction: Dogbone adapter cord is extremely flexible and is coated with a heavy-duty flame retardant, heat-resistant PVC sheath that serves as protection from wear and tear, as well as outdoor elements. Hassle-Free PowerGrip Plug. The patented PowerGrip handle eliminates frustration by assisting users in safely and conveniently gripping, plugging, and unplugging the female end without straining or damaging the adapter.