Tapered caps and plugs provide excellent protection against damage, dirt, moisture and corrosion during storage and shipping. Single units may be applied as either caps or plugs. All provide secure fit and are easily removed. Specifications: Standard Color: Blue. Standard Material: Polyethylene. When used a plug €œA€ dimension should be 1% large than the inner diameter of the part. Minimum of .020€. When used as a Cap €œE€ dimension should be 1% smaller than the outside diameter of the part. Minimum of .020€.