Transportation-Bicycle's customers have bought 3 kinds of detection instruments here
Level 1:
Statement: The following testing instruments are based on the customer's purchase behavior, not officially recommended, only for reference!
Genuinegoods
Raul Formula Guide with 215 international standard Colors
Leneta 2A sealed Opacity Chart
LANDTEK CM8822 platings Thickness Gauge measurement of nonconductive coatings on magnetically permeable objects and nonconductive coatings on nonmagnetic metal substrates