NiSi explosion proof filters slide into matte boxes or clip on to lenses to protect your glass from projectiles and impacts that could do irreparable damage. These filters are water white clear filters with no image distortion that have been coated with a shatter-proof film to keep all of the pieces together in the event of a shattering impact. That keeps all of the glass together and, more importantly, away from your lens in the event of an impact.