The YorkCo Smoke & Ammonia Mask used a Kops Tissot Monro (K.T.M.) facepiece with a set of proprietary filters, which used an unusual clamp to attach to the hose.  The mask and filters were stored in a metal box with the York logo on the front, and instructions for use on the inside cover.  Manufactured for York Ice Machinery Corporation by Mine Safety Appliances.