Zoom icon Click to expand Tap to zoom Chevron down icon Chevron down icon Stone and Mounting Gauge by Grobet Sale $37.20 | / SKU 35-558 1 2 3 4 5 6 7 8 9 10+ Quantity Chevron down icon Quantity Add to cart Spinner icon Notify me when back in stock Email address Email me when available Stone and Mounting Gauge The holes in the gauge are used to measure stones, while the extensions are used to measure mountings. One side shows millimetres, the other side shows the corresponding carat measurements.