VTech DS6151 2-Line Cordless Phone System for Home or Small Business with Digital Answering System & Mailbox on each line, Black/silver DECT 6.0 digital technology provides the best sound quality, security and range in cordless phones Interference free for crystal clear conversationswont interfere with wireless networks and other electronic devices Protect yourself from identity theft with digital securityyour call is digitized and encrypted, making it nearly impossible for someone to eavesdrop Digital answering system (includes a mailbox for each line) with remote message retrievalcall in from anywhere to get your messages Expandable up to 12 handsets using only one phone jackuses DS6101 accessory handsets. Note-if messages on the answering system are very difficult to hear press volume on the handset or telephone base to increase the speaker volume. If hear noise on the cordless handset and the keys do not work make sure the telephone line cord is plugged in securely