These are Neutral Density Filters used for Cinematography. They have a Neutral Density of .15, .3, .6, .9, 1.2. A common use for these filters are to allow the use of larger apertures, reducing depth of field to allow selective focus and rack focus.
WARNING: This product may expose you to chemicals which are known to the State of California to cause cancer. For more information go to www.P65Warnings.ca.gov.
If you want to share this elsewhere, you can click the link below to copy it