Accessory Handset for IS7121 VT-IS7101 The VTech IS7101 Accessory Handset is an accessory handset only. It requires the VTech IS7121-2 DECT 6.0 Expandable Cordless Phone with Audio/Video Doorbell and Answering System to operate. As part of the IS7121 series, the IS7101 Accessory Handset is like caller ID for your front porch by showing you an image of who’s at the door. The system’s video doorbell takes a photo and sends it to the handsets so you can screen visitors before answering the door, without worry of being seen. Always know who’s calling, even when you’re in the other room. This handset announces the names of your callers through the speakerphone.