I bought this to replace my cheap rubber block for port freight. All I wanted was something that used more of the available grinding surface, allowed for quick blade changes, and was strong and comfortable to hold. I got this block and I just said WOW! He met all of those criteria, and then some. Now I can use about 95% of the sandpaper instead of wasting almost half of it. Reed changes are quick, easy and intuitive. The block is very comfortable to hold, which gives me a secure feeling when grinding parts. Also reduces fatigue. I used it for a few hours the first day and after that I had no more pain. I'm used to my hands getting sore and my ankles numb after such a long time. I really enjoy my work now! Fantastic product and worth every penny. Just as important, if not more so, than the sandpaper that goes on it.