The Spyderco Pocket Stone is a small rectangular pocket stone for portable field use and honing small items.
Pocket Stones are available in medium grit (this listing) and fine grit. The 303M Medium Grit Pocket Stone fits in the palm and is packaged in a leather carrying case. It is autoclave safe (ideal for dental tool sharpening) or can be cleaned with a plastic scouring pad and powdered abrasive cleanser.
1" x 5" x 1/8" (25mm x 127mm x 3.2mm)
Information from Spyderco