A low grit stone is a must for knives that have not been sharpened for a long time, or have sustained an accident in a kitchen (chips & missing tips, for example). In addition, it is a great stone to have for single bevel knives as most single bevel blades will need a bevel setting that can take a while. It will remove necessary materials quickly without tiring the sharpener allowing you to move through the stone progression in a timely fashion. If you are an experienced sharpener that needs to sharpen many blades repeatedly, having the right low grit stone can make all the differences. 

Brand: Hitohira 
Product Type: Whetstone
Grit: #150
Soaking Requirement: 10-15 min
Size: 210 x 80 x 50mm
Weight: 1721g