The Lee Professional Kit is two Foundation Kit holders linked together by a connector which allows independent rotation of each holder. This gives great flexibility to the studio photographer wishing to use several filters (up to 8) simultaneously, and also allows use of a 100x100mm polariser in the front holder in conjunction with graduates in the rear holder. Note that this holder is only suitable for use with normal to tele focal length lenses. Vignetting will occur with lenses beyond modest wide angles with all formats.