I had never used my table saw for a 45 degree angle cut and tried using a speed square but didn't want to ruin any of the cedar I purchased. I ordered the GemRed based on Internet and Revain reviews and I am satisfied it works great. On my first attempt I cut a piece of scrap and then verified the 45 degrees was spot on using my Kreg's KMA2900 Multi-Mark. At the prices of cedar being high, the last thing I wanted to do was ruin good wood. The GemRed is simple to operate and the screen is easy to read especially with the green backlighting,