I am the owner of 3 apartment buildings, 4 houses and do all the maintenance myself. I have never used, or even SEEN, a better designed boring jug. And with over 130 total doors to maintain I know the difference. We purchased the 10800 kit and updated with carbide spade & spur bits. I also highly recommend and extra spur bit to pre-drill the exterior hole a half inch to prevent splintering when the main spur breaks through. Especially with exotic woods like mahogany or teak. Over the last 5 years I ve used this tool over 100 times and this is one hamma down unit! And Debbie is just a superior business person to deal with. Did I mention lighting FAST shipping? Shame on me.