This Watson Model 100 Bulk Film loader takes 100 foot bulk reels of 35mm film and lets you fill your own reusable cassettes (three are included.) Why bother? Well, it can save you some money if you’re shooting a lot of film- butyou can also customize roll length based on what you’re up to. Need a 5-shot roll to check out a lens? 10-20 for a quick jaunt around the block? Well, you can do it. Convenient!