Personalized Mechanical Engineer Gear Sketch Toddler Long Sleeve T-Shirt. Mechanical Engineer text across a gray sketch of a gear is a unique engineering design for engineers and engineering students at birthdays, holidays and graduation. A classic for Fall, Winter and Spring, these long sleeve toddler t-shirts are sure to be a staple in your child's wardrobe. Whether layered or alone, this t-shirt is soft yet durable enough to stand up to your toddler's playtime demands.