This is a genuine manufacturer-approved replacement dipstick that is specially designed for use with DeWALT air compressors. It allows a user to check the oil level in the unit. Remove the oil dipstick to read oil level, oil should not exceed top raised line (MAX) on dipstick. If oil is below lower mark (MIN), add high-quality synthetic o...Read moreil. It is made of durable plastic with a rubber o-ring and it is sold individually.