In my business my employees and I need to have cordless phones. I purchased the RCA system that is available here (with cordless units that need to link to the base units). After replacing all the cordless units multiple times with tech-support over a year and then having the warranty expire I felt the need to find another more reliable system. I found the Panasonic 4 line system with cordless handsets, but the reviews reminded me of my problems with RCA....so no go.I splurged and bought a true business system from ESI. Awesome and it does more than we ever thought we could have.....except for the cordless handsets. At $500.00 a crack we could not afford the digital cordless units.But then I find the Plantronic Voyager 510. With the HL-10 lifter it works with my ESI desk phone. I am cordless and HANDSFREE TOO! I can walk around my store with no loss of signal. I expected the 30 ft coverable would be marginal, but I am sure I am getting at least 40 ft of coverage.Many of my customers insist on calling me on my cell phone and others call into the store. No problem with my Voyager. Regardless of which system they are calling me on....just click the button on the headset and we are connected. No switching from a cordless phone to my cell phone.I can not recommend this product more highly. No product has been so easy to install, get up and running, AND provide exactly what was advertised. When it comes to tech products that is a rarity.