Ergodyne. Part of the Extreme Warming product line, N-Ferno 3-Layer FR Winter Liners are available in regular and shoulder lengths (styles 6873 and 6877, respectively). The liners feature three layers of warmth and protection, including a cotton shell, foam midlayer, and poly-fleece liner. Additionally, warming-pack pockets, hook-and-loop chin wrap, and hardhat suspension attachments offer an easy-to-wear cold-weather solution. 800.225.8238.