Star Trek Hats - Engineering You're going to look great and keep the sun out of your eyes with this Star Trek Engineering Adjustable Black Hat that carries the yellow insignia of the Engineering branch right on the front of the cap. The Star Trek Engineering Adjustable Black Hat is a structured brushed cotton twill 6 panel cap. Fully adjustable, the cap's back feature's a mid-profile flexible velcro closure with the Roddenberry logo. One size fits most adults.