The Steel channel length is 18" the entire assembly with top guide and bottom shoe is 19". The channel width is 5/8" at the open side & 35/64" at the solid side as measured with a digital caliper.
There are some hard to read letters on the back of the channel (photo attached) and look to read "17 4 KF CALONELL"
I think it is probably a series 395 but just want to make sure before I order.
thanks for your help
David