Disclosed herein are delivery devices for delivering a volume of a drug product, placebo product, or other product including a fluid. The devices may include a barrel having a longitudinal axis, a proximal end region, and a distal end region. The proximal end region may include an opening, and the barrel may be configured to receive a drug therein. A plunger rod may be disposed at least partially inside the barrel and protruding from the opening. The plunger rod may include a rack having a plurality of teeth. The device may further include a pinion having a plurality of teeth configured to engage with the plurality of teeth of the rack, and rotation of the pinion against the rack may move at least a part of the plunger rod along the longitudinal axis of the barrel.
