In an embodiment, a resettable injection training device and a method embodiment for resetting the device is provided herein. The device may include a housing having a proximal end and a distal end, the housing defining a cavity there within. A plunger may be slidable relative to the housing between the proximal end and the distal end. A releasably locking shield having a proximal end and a distal end, and being slidably engaged with the housing is also provided. The shield may be slidable between a retracted, pre-use position an extended, locked, post-use position. The device may further include a flat biasing member for locking the shield in the extended position, and a compressing component slidable relative to the housing, wherein pressure on the flat biasing member from the compressing component deforms the flat biasing member, and unlocks the shield, and wherein a release of pressure by the compressing component on the flat biasing member locks the shield in an extended, post-use position.