I used this product to drill (10) through holes in a 14" thick concrete wall (we used a Milwaukee extension and center piece). Works perfectly! Water is not required. A few holes, we encountered 1/2" rebar and the bit (carbide) cut through them. They stop every 3" to dislodge the concrete. We used a small 1" Milwaukee impact drill bit, to power the drill (remember you're only cutting a thin bend so you can take a 2-1/2" diameter core with a 1" impact drill) I hope this was helpful.