Maximize the value of Voice over IP communications with Plantronics DA Series USB-to-Headset Adapters. Paired with any Plantronics professional headset, the adapters enable VoIP softphone users to conduct crisp, cost-effective client interactions. The DA55 and DA60 are infused with digital signal processing for optimal call clarity, and SoundGuard Plus protects listeners from strident transmissions, and an echo suppression feature facilitates natural dialog flow. Our sophisticated DA60 adapter offers PerSono Pro software, which equalizes softphone audio settings and displays transmit and receive volumes for every call. The Plantronics DA40 USB-to-Headset Adapter is ideal for enterprise offices meeting aggressive price point requirements. A tiered range of adapter solutions fits the budget and business requirements of every softphone-based organization. Voice over IP headsets are becoming more popular as technology allows you to talk over the internet and save money with less long distance charges on standard telephone lines.