Digital-Tyre-Tread-Depth-Gauge-Calibration-Charge-Sealey-VS0563CAL-Our-VS0563-has-a-VOSA-approval-which-covers-the-initial-calibration-of-the-tool-at-the-factory-The-unit-is-supplied-in-a-sealed-box-Once-the-seal-is-broken-the-calibration-cannot-be-guaranteed-We-do-not-supply-a-certificate-of-calibration-for-this-initial-period-RE-CALIBRATION-SERVICE-We-offer-a-competitively-priced-calibration-service-&-recommend-the-unit-is-returned-to-us-annually-for-re-calibration-A-test-certificate-