The Fineline Masking Fluid Pen is a 1.25 oz. bottle with 1 in. 20g fine stainless steel needle applicator tip. The 37.5ml bottle contains Finelines proprietary hypo-allergenic liquid latex masking fluid, allowing users to precisely apply the masking fluid to a variety of surfaces. Refillable; the unique cap wire closure system maintains an air-tight seal so that the masking fluid never dries out and is always ready to use. Draw fine lines and designs on a variety of materials including paper, canvas, ceramics, finished wood, metal, plastic and glass (not for use with fabrics). Hypo-allergenic: Fineline Masking Fluid can be used safely by individuals who are allergic to natural latex rubber. Unlike other masking fluids that require removal within 24 hours, Fineline Masking Fluid can remain indefinitely without staining. No tool or eraser is needed to remove the masking fluid. Fineline Masking Fluid simply lifts off the surface.