Food grade material. 
Save for using.
Flexible that makes customer feeling well.

Features: 

1.Cheek Retractor to help open your mouth wider during teeth whitening/bleaching or other dental treatment.
2.Medium size that can fit the kinds of people.
3.It can help your open your mouth wider to avoid the stimulating drugs access on your lips.
4. You are welcome custom orders.

Kinds of material, shape, color, size, packing are ok to custom.