One 4000 ft spool of 9 gauge (0.114in) aluminum wire made from high grade alloy with bright, shiny smooth finish to make it highly visible to livestock & humans. Conducts electricity 4 times greater than steel. Lightweight - one third the weight of steel. Easy to re-spool, ideal for controlled grazing. Greater flexibility, can be hand twisted & tied. Compatible with any charger or accessories. Made in the U.S.A