It features two files

For use with propane gas

providing the most storage space

6+1 bearing system for ultimate smoothness

natural and synthetic materials

Smartwool Heathered Rib Color:Chestnut It features two filesDescription Smartwool Heathered Rib A no nonsense ribbed sock with built in, cushioned comfort and a touch more cushioning than our Classic Rib. Sock Height: Crew Signature Smartwool sock Ribbed leg Extra cushioning Virtually Seamless toe for enhanced comfort Made in USA of Imported Yarn: 61% Merino Wool, 37% Nylon, 2% Elastane Machine Wash Warm, Wash Inside Out. Do Not Bleach. Tumble Dry Low. Do Not Iron. Do Not Dry Clean.