The Servus liner is made of thermolite, is packaged 12 pair per case, comes in black, meets ANSI Z41-1991, ASTM F 2413-11, CSA Z195-09, OSHA 1910.136 standards and is for use with Leather Upper Boot. Proper sizing is important when buying this part. The size for this product is 12. These types of parts are designed for specific applications which feature ways of safeguarding & shielding itself and/or the user. This part is designed and manufactured such that it offers the following protection: Puncture-Resistant.