All Miller 400 helmets produced after Oct. 1, 2002 will be serial numbered. This number can be found stamped into the helmet shell on the side block mounting area, behind the side block

Miller Diving has instituted a procedure for issuing serial numbers to Miller Helmets manufactured before October 1, 2002. This procedure will register the number assigned with Miller Diving as a permanent method of identifing the helmet. The Helmet owner needs to fill out and fax back to us a completed Serial Number Request Form.

A number will be assigned and a certificate issued for that helmet. The helmet owner will then engrave the number on the helmet following our recommended procedure. If your helmet has previously been numbered and you wish to have it registered, please include the number on the Request Form and we will issue a Registration Certificate for that helmet with your number. In the unlikely event of a duplicate number, Miller will issue a secondary number from our log for that helmet.