The Checkline SB-4H Traceable Steel Calibration Test Block, Size 0.250 - 1.000 " is ideal to check the accuracy of ultrasonic thickness gauges. All blocks are made from ultrasonically tested material and include NIST traceable Certification Reports and hardwood storage cases.

• Precision Machined and Finished
• Includes NIST Report and Test Data
• Includes Wooden Storage Box