Bosch HDC300 SDS-Max and Spline Hammer Dust Collection Attachment Chiseling dust collection shroud - focuses air suction from the vacuum around the chisel for maximum dust collection Unique ski-boot style clamping band - provides easy installation and adjustment onto the hammer tube Adjustable metal extension arm - provides easy adjustment for proper positioning around the chisel and can also accommodate different chisel lengths 3-piece adaptor set - allows the chiseling dust collection attachment to be installed on different size hammers 1-3/8-Inch dust port fits Bosch dust extractor vacuum nozzles