Caldwell Range Plugs Never lose your earplugs again with Caldwell Range Plugs with cord and clip. Caldwell designed these Range Plugs to have a tapered shape made of a polyurethane foam to make them easy to insert and comfortable for hours of use. The cord can be used in conjunction with the provided to clip to snap on the back or your hat or the collar of your shirt so you always know where your ear plugs are. – NRR 31 – Tapered design makes the plugs easy to insert – Polyurethane Foam makes the plugs comfortable to wear – Cord and Clip make it extremely east to keep track of – Screw Cap bottle makes storage of un-used plugs extremely convenient