One of the most important steps in placing a rock climbing bolt is cleaning the hole prior to installing the bolt. All dust and debris must be removed. Our brushes are made with Dupont Tynex nylon and have excellent wear resistance. Nylon is stiffer, wears longer and cleans easier than soft brushes. This brush is perfect for manually cleaning bolt holes for both glue in and mechanical bolts. The handle is made of twisted steel wire.