Personalized Hydraulic Engineer Plunger Drawstring Bag. Hydraulic engineer text with an image of a toilet plunger is a humorous gift design for hydraulic engineers, college students, plumbers and home handymen and women at birthdays and holidays. A durable and versatile cinch bag built to handle daily use. . With its lightweight design and reinforced corners, this pack is perfect for the gym, travel, or everyday activities.