Greetings to all from Puerto Rico...!   You can get the fiberglas croos boom from M2.   M2's Heavy Duty Fiberglass Cross Boom has been developed to work with the Yaesu G-550 Elevation Unit or G-5500 AZ /EL Unit. It allows solid clamping to the Cross Boom without crushing thin wall fiberglass tubes. The unit consists of a center solid 18" aluminum rod and (2) 2" x 1/4" wall x 60" long fiberglass tubes. The solid aluminum rod and thick wall fiberglass tube will give you the ability to secure large systems or arrays for years of solid slip free service. *Total length of unit when assembled is 11' or 132".   Visit the following link:   http://www.m2inc.com/   Then select HAM RADIO PRODUCTS In the next page select Rotators and accesories, next look the directory on the right Positioners and Accessories,  look at the bottom,  select the HD Fiberglass Boom Kit   73's Tony-KP4IA