Plantronics CS540 Headset + HL10 lifter - 84693HL10

At only 21 grams, the CS540 features the lightest DECT headset on the market. That means all-day comfort for all-star performance. And now, it's better. Increased range for maximum mobility, one-touch controls, energy efficient power management, simple plug-and-talk installation — the CS540 does it all.

Range up to 350 feet away for maximum mobility
DECT technology provides better audio, eliminates interference from Wi-Fi networks
Up to 7 hours talk time.
Convertible from over-the-ear to over-the-head - tailored for comfort
Premium wideband audio quality, noise-canceling microphone
One-touch call answer/end, volume up/down, mute, and flash controls
Smart power management system optimizes for range and talk time
New headsets can subscribe to a base by simply docking the headset
Requires HL10 Handset Lifter or Electronic Hook Switch cord for remote answer/end.

Includes Electronic Hookswitch Cord for remotely answering and ending calls (Not applicable to ShoreTel IP Phones)

The following Avaya telephones are compatible with the CS540 and do not require the additional HL10 accessory (not included) to obtain full hookswitch control and ring detection.
1408, 1416
1608, 1608-I,1616, 1616-I
2410, 2420
4610SW, 4620, 4620SW, 4621, 4621SW, 4622SW, 4625SW, 4630, 4630SW
5410, 5420
5610, 5620, 5621SW
6416D+M, 6424D+M
9404, 9408
9504, 9508
9608, 9611G, 9620, 9620C, 9620L, 9621G, 9630, 9630G, 9640, 9640G, 9641G, 9641GS, 9650, 9650C

CISCO:
Cisco SPA500 Series - SPA512, SPA514, SPA525G2
Cisco 6900 Series - 6945
Cisco 7800 Series - 7821, 7841, 7861
Cisco 7900 Series - 7942G, 7945G, 7962G, 7965G, 7975G
Cisco 8800 Series - 8841, 8851, 8861
Cisco 8900 Series - 8941, 8945, 8945G, 8946, 8961, 8965, 8965G
Cisco 9900 Series - 9951, 9971

POLYCOM:
Polycom SoundPoint IP Models - 320/321, 330/331, 335, 430, 450, 550, 560, 650, 670 (running SIP software 3.0 or later)
Polycom VVX 300, 310, 400, 410 (running UC software 4.1.4 or later)
Polycom VVX 500 (running UC software 4.0.1 or later)
Polycom VVX 600 (running UC software 4.1.2 or later)
Polycom VVX 1500 (running UC software 3.0 or later)

SHORETEL:
Shoretel IP phones support 'Load Detection' and do not require an Electronic Hook Switch cord or HL10 handset lifter. The CS540 connects directly to the headset port on the bottom of the phone.
For users who often answer their headset while away from the desk, the RD-1 ring detector can be added to the CS540 wireless headset. The RD-1 sends a ringer alert to the headset when your desk phone rings (sold separately; see drop down option above)
ShoreTel IP Phones - IP 212K, 230, 265, 420, 480, 480G, 485G, 530, 560, 560G, 565G