A longer filament hub to fill in large gap between Ender 3 V3 SE included holder and filament spool. The original design is a great idea but when changing spools often it became a hassle to put hub halves back in each time and get out again. With this model you glue ( I used hot glue so can be removed if want to) the two halves together around the factory holder making sure not to get glue in between hub and factory part so it spins freely. Now you can just slide spool on and clip at end. The clip is unchanged from EL'Scorcho's design and Thanks to him for his good work.