Bosch HDC400 Hex Chiseling Dust Collection Attachment, 1-1/8" Unique clamping band with ski-boot type clamp provides easy installation on the hammer Flexible clamping band allows the hose to be adjusted up or down in the band to accommodate different chisel lengths Dust port fits Bosch 1-3/8-inch vacuum nozzles and can also be converted to 1-1/4-inch or 2-inch nozzles using the appropriate adapter Floating rubber shroud allows the shroud to flex up or down should the shroud contact the workpiece during use