This small and unobtrusive E10 inline adapter is compatible with all Poly headset styles. It is ideal for connecting headsets to telephone systems where access to a handset is not required. The E10 adapter features a volume control which allows users to adjust incoming calls to a comfortable listening level.Product Features: - Volume control - SoundGuard Plus and Call Clarity ensure optimum sound quality - Can be used with all Poly Contact Centre and Office headsets - Two-year warranty