|Similar to the S-655, the 3M S-657 Hood uses a double shroud design for its respiratory seal; wearers can select on their seal design based on personal preference. The wearer should tuck the inner shroud into a shirt or protective coverall, which allows excess air to be channelled over the body for additional comfort. The 3M S-657 Hood offers head, face, neck and shoulder coverage as well as providing eye and face protection to EN166 - liquid splash and low energy impact (grade F) the same classification for impact resistance as safety spectacles! Manufactured using a general purpose, fabric, the S-657 is a cost effective, practical powered air solution. When used in conjunction with 3M Powered and Supplied Air Systems the S-657 offers an assigned protection factor (APF*) of: , Jupiter APF= 40 , Dustmaster APF= 10 , TR-300 APF = 40 , V-500 APF= 40 Assigned Protection Factor (APF) as detailed in HSE HSG53.