Work Sharp Precision Adjust is a fantastic sharpener. However, it's limited by stock sharpening stones mounted on the proprietary holder.
Premium 4" Stone Holder for Work Sharp Precision Adjust overcomes the limitation. As of today, you may use any 4" sharpening stones including the KME form-factor and Venev Dog Series dual-side diamonds. Premium Stone Holder is made of metal.
Note. It's very important to keep a sharpening angle consistent. The angle should not change when progressing to the next stone. If the thickness changes, the sharpening angle changes. Unchecked, this can ruin your sharpening. Use a digital angle gauge to monitor the sharpening angle when you replace a stone in the stone holder. Use the angle adjustment knob of the sharpener if necessary.