Matt is monel
A rigid or flexible item of various shapes attached to a structure for the purpose of providing access for inspection, service, replacement of components and/or adjustments or mounting operations. It is designed to be attached by means of bolt holes, slots, mounting ears, tabs, and the like. To permit access, the mounted cover requires partial or complete removal. It may include an observation window. For items permanently attached by hinges and the like, see door, access (as modified). Excludes all covers not specifically designed to provide access for the purposes listed above.
Classification: Other articles of iron or steel not wire nesoi
NSN 5905-01-450-5794
NSN 5945-00-826-9772
NSN 5996-00-465-8261
NSN 5996-01-039-2704
NSN 6620-00-593-5313
NSN 6650-01-461-7713
NSN 2925-01-004-5627
NSN 5905-01-427-3804
NSN 6135-00-519-1325
NSN 6610-00-092-7380
NSN 6135-01-397-6564
NSN 5975-01-605-1999