This is a brand new T390ZR2 20" guide bar made by Tsumura. It is compatible with chainsaws from various brands including Cub Cadet, Dolmar, Husqvarna, John Deere, and Jonsered among others. The guide bar has a .325" pitch, .058 gauge, and 78 drive links.
Assembly is required, and the guide bar is designed for use with 2-stroke gasoline chainsaws. This item is sold as a single pack
pic of fitment is a good starting point to see if its compatible with your chainsaw.