Mast slide - 14 mm. For 14 mm dia mast, nickel plated brass, 70 x 38 mm base.
A traditional style mast slide that takes a 14 mm diameter mast.
The staggered holes permit fine adjustment of mast position.
The sliding plate can be adjusted to take larger diameter mats - up to 19 mm - by carefully filing out the hole to a larger diameter.