Max Coupler 8k - 18XL by C U Off Road

A longer version of the original with just over 12 inches added to the main body with a few extra holes for versatility. 

The main body that slides into the receiver is 18" long, plus the front rotational head. 

The holes are 1 1/2", 4 1/2" and 13 1/2" from the rear back end of the body.