An adjuster having a housing or lamp housing with an adjuster portion, a gear positioned inside the housing or adjuster portion, a control rod engaged to the gear and extending from the housing or adjuster portion, and at least one tang outside the housing or adjuster portion such that the tang engages the control rod and prevents rotation thereof. As such, rotation of the gear results in linear movement of the control rod. The adjuster may be positioned on a lamp housing, or other structure.