Question about Gigaset Comfort 500 A Duo (CH-Version)

Can I add more phones? Which Gigaset models are compatible?

The Gigaset Comfort 500 A Duo (CH-Version) are analogue telephones. In terms of Box100 compatibility, these phones are designed to work with analogue telephone lines and are not specifically designed to be compatible with IP telephony systems or boxes such as Box100, which are typically used for telephony over IP.designed to be compatible with IP telephony systems or boxes such as Box100, which are generally used for IP telephony.

If you require compatibility with Box100, it would be best to check the specifications of Box100 and contact the manufacturer for more precise information on device compatibility.