This standard length J-Mount has a 2″ OD mast which is typically used the new DirecTV Slimline, AT&T, Viasat, Wildblue, Exede, and other satellite dishes that require a 2″ OD mounting bracket / mast!
This mount is no longer available as the company that offered it is no longer in business, please see:
https://lonepinetechnology.com/product/directv-slimline-and-att-2-j-mount-brackets-single/