The HobbyZone Millennium PTU is an indoor-only RTF electric helicopter marketed and distributed by HobbyZone, a division of Horizon Hobby of Champaign, Illinois USA. Introduced in the summer of 2007, the two-channel Millennium PTU (for "personal transportation unit") is the first low-cost helicopter of its type to utilize both 2.4 GHz radio technology as well as lithium polymer battery technology. A great many other inexpensive indoor helicopters depend on infrared control instead of radio control. Like those infrared-control helicopters, the Millennium PTU requires no previous flying experience.