What they are, V blocks. I haven't tested them for quality as I don't have an equalizer or other concurrency checking hardware, so don't expect great accuracy.
12X9X3 Inch Granite Surface Plate With No Ledge - Perfect For Precision Measurement
9 Review
β‘ Pro Fluke T6 1000 Electrical Tester for Enhanced SEO
5 Review
π‘ Enhanced Fluke T6-600 Electrical Tester: Boosting Efficiency and Accuracy
4 Review
π Enhanced Connectivity with Fluke IR3000FC Infrared Connector
6 Review
π§ UEi Test Instruments DAFM3B Digital Multimeter
6 Review
π¬οΈ Advanced 3-in-1 Indoor Air Quality Monitor with CO2/RH/Temp Data Logging and Audible Alarm - NDIR Sensor Technology
8 Review
π Dioxide Controller for Digital Gas Monitoring
5 Review
π Enhanced Precision with Backlit Professional Manometer for Differential Ventilation
6 Review