Nearly all VoIP phones can support a headset.  All of the Grandstream phones are compatible with a wide variety of headsets.  The only ones we sell ourselves are Plantronics DECT systems.  They are somewhat expensive, but work really well and have excellent support.  I personally use a Savi 700 which also connects to the computer and cell phone.

There are three main types of headsets.

1.  Based on DECT wireless technology with their own base.  These have very long range, around 100-150 feet in the real world.  Most people can walk around a medium office/shop without issue.  They cost more, with prices normally running between $225 and $275.  Many of them can also integrate with your computer and/or cell phone.

2.  Bluetooth, using the phone's built-in Bluetooth connection.  These are cheap, and are the same type you'd use with a cell phone.  We don't sell these, but you can buy them everywhere.  The real world range is around 30 feet, sometimes less, depending on the environment.  This document shows you how to pair a standard Bluetooth headset to a Grandstream phone:

3.  Wired headsets.  Again, most will work as long as they have a connector that is compatible with your particular phone.  Price ranges vary greatly, from below $10 to $70 or so.  For Grandstream, here is a list of supported headsets, although many others will also work: