Solid, heavy-duty, aluminum I-Beam frame, inlaid for a warp-free level, with select kiln-dried mahogany, and finished with 2 protective coats of clear, hand-rubbed lacquer. Shock-absorbing rubber end-caps screwed into place for durability. 2 clear curvedvials per sight, each solid-set by hand and protected by heavy glass lenses with a water-tight seal. 24"L has hand grips, remaining sizes feature hand holes. 1-1/8" x 2-3/8" frame.