United States Navy E-4/5/6 Aviation Machinist's Mate Rating Badge
Criteria: Worn by Aviation Machinist's Mates (AD) with ranks from Petty Officer 3rd Class (E-4) to Petty Officer 1st Class (E-6). Aviation Machinist's Mates are typically assigned to billets that focus on the maintenance of turbojet aircraft engines and their equipment. They maintain and repair/replace all of the aircraft engines and accessories, as well as preform the duties associated with flight engineers.
The badge is sold with all 3 chevrons below the rating for E-6, and can be tailored down to the other two chevrons.