30 CFR § 23.10 - Material required for MSHA records.
In order that MSHA may know exactly what it has tested and approved, it keeps detailed records covering each investigation. These records include drawings and actual equipment as follows:
(a) Drawings. The original drawings submitted with the application for the tests and the final drawings which the manufacturer must submit to MSHA before the approval is granted, to show the details of the device as approved. These drawings are used to identify the device in the approval and as a means of checking the future commercial product of the manufacturer.
(b) Actual equipment. If MSHA so desires, parts of the devices that are used in the tests will be retained as records of the equipment submitted. If the device is approved, MSHA reserves the right to require the manufacturer to submit one, with the approval plate attached and without cost to MSHA, as a record of his commercial product.