Interchangeable Head Pivot Type Knurling Tool- Metric Standard Raises an angled ridges in a diamond pattern on any work-piece for a decorative finish or slip proof grip. Holder size: 3/4" x 3/4" x 4.5" ( 19 x 19 x 113 mm ) Diamond Pattern Knurl dimensions: 3/4" (Diameter) x 3/8" (width) x 1/4" (Bore)- Pitch 1.5 mm Linear Pattern Loose Interchangeability Heads of 1/4" & 3/8" Width both Epoxy Black Finish for a Rust free life