Works on analog, digital and tri-band phones. The Internal Antenna fits all cell phones except the Nextel 500 and 800 series. The Internal Antenna is device designed to capture stray radiation within the phone and re-radiate the signal to improve the phone's performance. This antenna is easy to install. Just slip it underneath the phone's battery, and enjoy clear, enhanced, static-free reception.
Uprights are awkward, and the bags they use are messy.
The large removable dust cup means you never need bags, and the filter is washable, so you can use it again and again. It includes a 20 foot power cord which extends the range of operation. A 5mm light flashes when the alarm sounds, for the hearing impaired.