Personalized Hydraulic Engineer Block Toddler Long Sleeve T-Shirt. Hydraulic engineer text with a decorative line sporting two drops in a colorful block, is a unique design for 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.