Each set of 5/8-16 UN thread ring gage 100% calibrated with quality assurance in our factory. If clients need long form calibration certificate, we can send to professional third party testing lab ISO17025 accredited to get. it need USD35 extra fee per set.each set including GO NOGO. We will send out goods by DHL, Fedex or UPS. Clients can expect goods in quick time. As too many items in stock, we haven't take pictures one by one, the picture showed just for reference.