The UMB-1 Universal Matte Box (Base) is the entry configuration in Wooden Camera's UMB-1 system, mounting to 15mm LWS rods on a height-adjustable bracket. It has a 143mm diameter opening, sized to fit lenses up to 143mm O.D., and carries two rotating 4 x 5.65" filter stages as standard, with an optional third stage available as an add-on. NATO accessory rails run along the left, right and top of the housing for mounting further accessories. A universal cloth donut with easy-to-grab finger loops is included, sealing the gap between the matte box opening and non-standard lens diameters, along with a folding top flag that blocks stray light from above the lens and folds flat for storage. As the fixed-bracket entry point into the UMB-1 range, it shares its opening, filter-stage and rail layout with the Clamp On, Swing Away and Pro configurations, differing in its mounting bracket and included accessories.