If you've got a Polaroid SX-70, you might be a little bummed that all our special edition film packs are for 600 cameras only. But don't worry – these Neutral Density filters slot over the top of 600 cartridges, changing how much light the film receives. And just like that, they make any 600 film compatible with SX-70 cameras. They're completely reusable, too, so they should last you a lifetime. Just don't throw them out with the cartridge when you finish a pack of film – seriously, it happens all the time.