Actually you drill your own holes. You lay your old steel edge on top of the urethane edge, and use it as a template. It drills pretty easy, just dont try to cut it without a skill saw. We actually heated a skill saw blade up so much it warped the blade.<br>Anyway, if you have a full trip plow, we would order you a 10" wide edge, and you can center drill it. Wear one side up to the steel edge and then flip it to wear the other side.<br>It wont work that way with a bottom trip plow. When the bottom trips the extra amount of edge hanging up over the moldboard will trap snow into the trip area, and cause the trip edge to get jammed up. So we only recommend a single edge for them.<br>We also after wearing up to the steel cutting edge, flip the steel edge upside down and gain even more life out of the urethane edge.<br>Dino<p>----------<br> Professional Ice and Snow Management <br>Products:Services:Equipment www.sima.org