10/22® Magazine Dust Cap-fits JÄGER 22-25W?? and Ruger® BX-25® Magazines-DARK EARTH. Made from durable NBR (Nitrile Rubber), our dust caps exhibit high tensile strength, as well as excellent abrasion, tear, and compression set resistance in temperature conditions ranging from well below 0 degrees Farenheit to those in excess of 200. Our rubber caps help protect the rounds in your magazine against dust, excessive water and other exterior contaminants.