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3.5mm Smartphone Headset to CISCO RJ9 Phone Adapter


Product Description

  • Convert 3.5mm smartphone plug to single 4P4C RJ9/RJ10 Cisco handset jack
  • Works great with Cisco VOIP office phones with a RJ9 headset jack
  • Save money by buying Smartphone headsets to use with your office phone's headset jack
  • Reduce clutter with single headset
  • Does not work with RJ11 jack, which is wider than your headset jack (6 positions vs. 4). RJ11 jack is what is in the wall. RJ9, RJ10, RJ22 are what is on your phone handset or headset.
  • Works with all smartphone headsets!

The PH35-RJ9Cisco adapter converts the standard smartphone headset single 3.5mm plug to a standard RJ9, RJ10, or RJ22 handset plug, allowing you to use your favorite headset with your Cisco IP phone. This adapter is designed for use with headsets that have one 3.5 mm plug. The adapter outputs binaural sound for stereo headsets, meaning you will hear sound out of both ears.

Why buy an expensive headset just for your office phone? Use the Headset Buddy Adapter and your existing smartphone headset with most Cisco VOIP office phones that have a headset jack. A money saver for home businesses, call centers, sales people, or anyone who is on the phone all the time, and wants to use a lower cost or more comfortable PC headset.

The adapter cable is approximately five inches long.



*Only compatible with Cisco and Ativa phones. Does NOT work with Polycom, Aastra, Nortel, and most other phones.

**Must be used in the headset port on your Cisco phone. This device WILL NOT work if plugged into the handset or RJ11 (wall) jacks.

This list is not all inclusive. Please look up the specifications on your specific phone to see if it has a RJ9, RJ10, or RJ22 headset jack. If the Headset Buddy doesn't work with a model on this list we will be happy to refund 100% of your purchase plus pay for return shipping.

Incompatible Cisco phones:

7902, 7905, 7910, 7911, 7912, 7920, 7921

Compatible Cisco Phones:

6921, 6941, 6961


7940, 7941G, 7942G, 7945G

7960, 7961, 7961G, 7962G, 7965G

7970, 7971, 7971G, 7975, 7975G

7985, 7985G

8941, 8945, 8945G, 8961, 8961

9951, 9971



CTS 500

Please let us know if you find more compatible phones or incompatible phone models.

Product Videos

PH35-RJ9Cisco Demo 01:09

3.5mm Headset to Cisco Phone adapter

  • Headset Buddy Video Thumbnail Preview Image
    PH35-RJ9Cisco ...
    3.5mm Headset to Cisco Phone adapter

Warranty Information

Free returns, always!

We have a 30-day, no-questions-asked return policy for all of our products as well as a one-year, 100% Satisfaction guarantee; we’ll replace your HeadsetBuddy for free within the first 12 months.