Material: medical grade liquid silicone Size : adult size, children size 1.a breathing device that is placed over the mouth and nose; supplies oxygen from an attached storage tank. Silicone rubber oxygen masks are better than plastic masks. all of our oxygen mask made of medical grade liquid silicone. 2.not only provide better comfortable feeling ,but also provide a good seal for long-duration use by aviators, medical research subjects. 3.great price and best service, at the same time,to meet the stringent quality requirements of the Medical & Food Grade Products industries, a new cleaned workshop over 2000 was built .Now our TYM company is growing more and more confident with our services. welcome your OEM/ODM order.