LaCrosse Flex Shield Insole. Worksite hazards are always lurking. Put your foot down with enhanced underfoot comfort and protection that EXCEEDS safety standards! Nails, iron shards, glass, scrap metal... worksite hazards can get the best of even the toughest boots. Better call in some back-up... better get the Flex Shield Insole from LaCrosse! Its Lenzi L-protection barrier exceeds the ASTM F2413-05 requirement for a puncture-resistant midsole by 70 lbs.! That's in addition to adding extra heel cushioning and reducing slip and hot spots underfoot with its microfiber top lining. Plus, the P4 barrier is non-metallic, making it ideal for coder climates.State Size, as available in the Shopping Cart.