If you are looking for a high-quality tool to measure the dimensions of your parts, this Mitutoyo 611165-541 Gauge Block is the ideal choice. The 1/8″ L x 3/8″ H gauge block is made of steel and has an ASME AS-1 grade. It also comes with a certificate of inspection. If you need to inspect dimensional quality in your manufacturing process, this rectangular gauge block will help you do just that.