This product is made of high quality 3mm thickness neoprene rubber. Wearable head circumference from 55cm to 62cm.
 
Please note: this mask cannot use a breathing bag.
 
      If you have any questions about the product, please leave me a message because of the time difference. I may not be able to reply to you immediately. I will reply to you as soon as I go online     
 
 
 If the product has quality problems, please contact me immediately. I will immediately arrange the return and replacement for you