The Gun Butter Pen Oiler puts a precise drop of synthetic lubricant exactly where you want it. Gun Butter is a synthetic firearm lubricant engineered for high film strength, a wide operating-temperature range, and long-lasting corrosion protection. Key Features Pen-style applicator for one-drop-at-a-time precision on pins, springs, and detents Ideal for detail work and field touch-ups with no over-application or mess High film strength with a broad operating-temperature range 1/4 fl oz