B-17 Chin Turret Machine Gun Slot Cover with zipper; Skinner'sTackle Twill and Crown zipper; 1944. Machine Gun Bendix Turret Slot Installation Using Crown Size 10 Fastener; William Skinner and Sons (Holyoke, MA) Tackle Twill fabric and felt; 1944. Army green viscose rayon Tackle Twill and felt; This is a length of fabric with a double-action extra heavy zip fastener stitched down the center, from which protrudes a metal tube through which a machine gun barrel would be able to move up and down in the chin turret slots on the later version of the B-17, with the cover providing some extra streamlining. Golden brass 0.5 inch grommets on edges throughout pressed through felt. Metal zipper. Trademark Tackle Twill by William Skinner and Sons. Triple stitched double acting zipper. Photo of slot cover in use included in accession folder.