1/4" ID x 1/2" OD - Therm-o-Blue - Requires clamp #113, 1113, or 30-4. Therm-o-Blue and Therm-o-Red are made for air, water, and moderate chemical application. Prime PVC with ORS additives to increase the amount of resistance. The non marking cover is available in bright Red or Blue. Working pressure is 300 psi. Can be cut to length. Priced by the foot.