The Manfrotto SYMPLA Flexible Mattebox Complete Kit adds to the Mattebox itself a SYMPLA Variable Plate and two 12" long, 15mm diameter rods to make up a full system that's short of only a camera and lens and that's adjustable at several points which increase compatibility with lenses and which likewise increase ease of use.
The Flexible Mattebox is an unconventional mattebox that instead of the traditional French flag design features an accordion-like rubber hood that serves many purposes, very effectively. It allows universal compatibility with lenses from wide to long; it can be pressed up against glass -- when you need to shoot through glass -- to just about completely block out reflections; it protects the lens against knocks and scrapes; and it packs flat for transportability.
The Mattebox sits on an included SYMPLA component called the Universal Mount, which mounts the included 15mm rods and takes the weight of the Mattebox onto itself and the rods, and by which the Mattebox can be moved back and forth along the rods until locked into position. It additionally has a bar on which the Mattebox can adjust vertically 50mm to align with lenses of different lengths and heights, and it furthermore has a hinge by which the Mattebox can be made to slide aside 90° to allow for quick lens swaps (please click on "More Images" above to see an example).
The included Variable Plate is a quick-release camera plate that adjusts at a lateral axis to offset the camera from the plate's center, at a vertical axis to align the plate higher and lower, and that adjusts back and forth along the rods, exactly the way the Universal Mount does and in conjunction with the Universal Mount.
Back to the Mattebox: like most matteboxes, the Flexible Mattebox is equipped with two 4 x 4" filter holders (one of which rotates to allow a polarizing filter to be angled correctly). But unlike in any other mattebox, the hood of the Flexible Mattebox is rubber, flexible, and can open partially or fully in just an instant.
Universally compatible with lenses from wide to long
Can press up against a window to block out all reflections
Protects lens when open; packs flat when closed for transport
One of two filter holders rotates to let the other be angled correctly
15mm Mount System
Mounts and moves along two 15mm rods
Vertically adjusts 50mm to align with any lens
Slides aside on a 90° hinge to facilitate lens swaps