Miller DuraHoist Confined Space 2-Piece Adjustable Upper Mast
Compatible with any TWO Lower Mast Extensions, not exceeding a combined 90 inch in height. In other words, this upper mast, unlike the One-Piece one, can be used with TWO lower masts as long as the total height of the two lower masts does not exceed 90 inches. Or to put another way, the combined height of the two lower masts cannot exceed 90" in height. For example, the 45" and the 57" lower mast can't be used together. Mast offset adjusts from 12 inches to 29 inches.
Height range on the DH-21 mast is 41" to 56". This may be too short for normal applications - so the addition of a lower mast will be needed.