THE T-5100 TROLL MASTER COMES IN 2, 4, 6, AND 8 FOOT LENGTHS. THE 8 AND 6 FOOT IS JOINED BY A COUPLER. SINCE THE ROUND BAR IS 1 INCH IN DIAMETER, BASES 205 OR 215 CAN BE USED TO MOUNT 1/2 OR 3/8 DIAMETER ROD HOLDERS.