The Sirius is the signature series yo-yo of Nathan Crissey. It was produced by YoYoJam in response to the requests of players that prefer the playability of full-metal yo-yos, so as a result, the Sirius continued more metal than other composite-material yo-yos before it. This would make it easy for the uninformed to mistake the Sirius for a full-metal yo-yo. Of course, it has O-ring response and a large C-bearing. This style of body would eventually be resurrected in the form of the SR-71.