The Constroption is a four sided lapping plate made of wood and leather. The wood and the leather are both surface ground to be very flat and each plate can be turned and locked in place. The four sides are loaded with .5 micron diamond from DMT, .25 micron CrOx, and the last two plates are Purple Phase and Zulu Phase. These are garnet based abrasives I make here at the shop. Purple Phase is about 40,000 grit and Zulu Phase is about 50,000 grit. The Constroption helps to maintain the finish on the edge and the bevel and feedback from customers support that with statements like “smoothest shave I ever got!”. I finish all razors which come to the shop on the Constroption. I’ve been using the same one for about seven years and they keep getting better. No need to reload abrasive. At $189 shipping included in the US, it’s one of the better deals in the straight razor world.