They are amazing they are so comfortable because of the velvet inside and the thermal lens also it has a double strap this mask is so safe my whole team trusts it. it is great alough I think they have stopped producing them now, I'm not sure but grab one as quick as possible or miss out if all else fails dye i4's are a great compromise or wait for my long waiting HkArmy KLR I hope you buy one though great mask defiantly worth the money