Designed for Patient Comfort in a Broad Array of Sizes. Smooth surface with light silicone coating designed to minimize discomfort. Color-coded hubs for easy identification. Wide range of diameters and lengths. Lengths from 1/2 in. to 4 3/4 in. Gauges from 18G to 27G. Ultra-sharp, tri-beveled stainless steel designed to result in minimal pain. Material: Stainless steel with plastic (polypropylene) hubs.