1/2" rigid copper tube size x 20', blue, pex stick, for cold water, use with 1/2" quick connect & brass pex insert fittings, w type b burst pex pipe rated 1100 psi at 73 degree fahrenheit, 375 psi at 180 degree fahrenheit, type b silane method pex has more anti-oxidants & thermal stabilizers which is critical for chlorine ratings & recirculation systems, type a,b,c are european system designations not rating/grading system for pex, do not use duct tape, pipe dope, threading compound, mineral/linseed oil, support pipe every 30" vertically & horizontally, protect pipe when entering/exiting slab or walls, do not kink or expose to sunlight, minimum clearance to water heaters, boilers, wood burning appliances 18", recessed lights 12", gas appliance vents 6", nsf-61 fda, csa/astm, upc listed/approved, 25 year warranty even when used with other manufacturers astm sdr-9 certified fittings, covers materials, labor & is not pro-rated.