One chuck - sharpens all sizes 3/32"-3/4". New push to stop splitting port - will not allow you to over split the bit point. Adjustable material take-off - allows user to change the amount of bit material to extend the life of your bits. User replaceable sharpening wheel - No tool needed. Cast aluminum point angle shuttle - added durability The DD750X shop model is designed for durability and has the flexibility required to sharpen the largest range of dull or broken bits-including split points and masonry bits. The DD750X also adds increased capacity, sharpening to bits.