37.75" Stainless Steel Drive Rod enables 36 inch test depth. Compatible with all Quick Connect Style Kits. This Drive Rod has 2.0″ increments along its length to count blows per 2, 4 or 6 inch increments. This is often the easiest way to use the DCP looking for consistency in blow counts. It can also be used with the Vertical Scale and adapters to calculate CBR values or psf.