Magnet Thingys are manipulatives full of fun and flexibility. They are a ripstop nylon tube about 8" long with a magnet securely sewn into each end. Kids can loop them together to make chains, use them to make bracelets and necklaces, use them as floppy magnet wands, and much, much more. They come in sets of six assorted colors.
Check this magnet board ideas blog post if you're looking for ways to support magnet play.