JO-DI Diamond Weight Gauge

The JO DI gauge allows you to estimate the weight of all popular shapes of diamonds without removing the stone from the mounting. The only caliper gauge that reads round, emerald, pear and marquis shaped diamonds. Made of anodized black aluminum with clear numbers. It also comes with a conversion booklet.
Booklet size 6.3" X 3.5" X 0.5" Inches (159 X 90 X 11mm)