Meets the new requirements of ASTM standard for leg protection for chain saw users (F-1897-2008). This standard requires that the chaps can stop a chain saw running at 2,750 feet/minute under controlled laboratory conditions. Made from Prolar"! material and available with and without calf protection. 90 Series chaps (JE90) use a 420 denier nylon cover material and have two sets of quick connect leg buckles. 94 Series chaps (JE91) use 1,000 denier cordura nylon cover material and 3 sets of quick connect leg straps and buckles.