40% smaller and nearly 50% more powerful than its predecessor Completely backwards compatible with the previous version -- no need to replace existing equipment Roam anywhere while talking on the phone -- even through 12 stories of a hotel or office building What do you get when you take our most powerful cordless phone/2-way radio system, increase its power and range by nearly 50%, and decrease the handset size by 40%? You get the EnGenius Ultra -- the most powerful cordless phone and 2-way radio available anywhere! This amazing 900-milliwatt system is 9 times more powerful than the 900MHz phones commonly found in many homes, and 4 times more powerful than the higher-grade 2.4GHz phones, giving you a cordless phone range like you've never seen! Get crystal-clear reception through 12 floors of an office building or hotel, 3,000 acres of farm and ranch property or 250,000 square feet of warehouses,Construction site or manufacturing plants -- all with outstanding clarity! Like the previous incarnation, the EnGenius Ultra system offers the convenience of direct, handset-to-handset 2-way radio communication completely independent of the base unit. This allows multiple handset holders to remain in contact with each other, even in areas away from the base unit, like at remote job sites or trade shows. Plus, there's no annoying group chatter or having to push buttons every time you want to talk. Just use it like you would a normal phone! The EnGenius system is completely expandable, allowing it to grow along with your needs. It's also completely backwards compatible with the previous version, so you can add the smaller and more powerful handsets to your existing EnGenius system! The system supports up to 4 bases with 9 handsets each. Altogether 36 handsets can share 4 telephone lines. The system offers a 3-level privacy and security process, Caller ID and Call Waiting ID with 30 number storage (requires Caller ID subscription from your phone service provider) and a call management feature, allowing you decide which handsets can receive incoming, transferred or 2-way radio calls. Other features include vibration mode, 4-line illuminated LCD screen for low-light conditions, announced or unannounced call transfer, a 3.5mm audio-in jack for on-hold music or sales messages, as well as mute, flash and last number redial buttons. A short and long antenna is included with each handset -- use the one that best suits your needs.. A NiMH battery pack upgrade is also available (sold separately), featuring an 80-minute fast battery charge, 3 hours of talk time and 40 hours of standby time. Other add-on accessories include additional handsets and protective leather cases for each handset. An optional outdoor antenna, which increases signal strength and range, is also offered.