The Diamond Products 05805 is a 4-1/2" Core Bore Premium Black Wet Core Bit (Part Number: BP4500) designed for professional heavy-duty drilling applications. Key Technical Specifications Diameter: 4-1/2 inches Standard Tube Length: 13 inches cored length Hub Size: 1-1/4"-7 threaded hub (fits standard mounted core rigs and hand-held core drill motors) Bond Type: POL (Segmented)Operation Mode: Wet drilling only