The Earlex 5000 Professional and 6900 Commercial HVLP Spray Stations come with a 2.0 mm (0.08") diameter needle and fluid tip that is the most versatile and can be used with a wide range of paints. However, Earlex also offers optional sized needles, including this 1.5mm (0.06") needle that is recommended for spraying oil base, oxide, primer, air-drying, enamel, varnish, marine paint, water-based stains, shellac and more.. In general, larger diameter needles and fluid tips are ideal for higher viscosity materials since they allow thicker materials to be sprayed where finish is not of paramount importance. Smaller diameter needles, in contrast, are more suitable for lower viscosity materials ensuring a higher quality finish. NOTE: it is important that you match your needle tip size to the paint type being used, the thickness of the paint and the desired quality of finish. Check your instruction manual for information on selecting the correct spray pattern, paint volume, spraying technique and maintenance tips.