This Masking Pen is an 18-gauge, 1" long needle applicator tip that comes with a 1.25 oz. bottle of masking fluid. It has a unique cap/wire system to ensure a continuous flow of liquid from start to finish. When closed, the cap maintains an airtight seal so that the masking fluid never dries out and is always ready to use. Use it to make precise, controlled lines, dots, or area coverage with ease. Apply masking fluid over the area to be protected, and let dry. Once dry, paint over the protected area and let dry again. Peel off the dried mask to reveal the uncolored area. Details:1.25 fl. oz. (37.5 mL)18-gauge (0.8 mm) line sizeStainless steel needle applicator tipConforms to ASTM D-4236