· 𝐎𝐧𝐥𝐲 𝐟𝐨𝐫 𝐇𝐁𝟔𝟓𝟓𝟎 𝐏𝐮𝐫𝐜𝐡𝐚𝐬𝐞𝐝 𝟐𝟎𝟐𝟏/𝟐𝟎𝟐𝟐: 𝐎𝐧𝐥𝐲 𝐟𝐨𝐫 HelloBaby Baby Monitor HB6550 2021/2022 version, not for HB6550 2023/2024/2025 version and other models such as HB65, HB50, HB6351, HB6560, HB6081... Please contact the seller before purchase. Not suitable for purchase outside the United States.· 𝐇𝐁𝟔𝟓𝟓𝟎 𝐀𝐝𝐝-𝐨𝐧 𝐂𝐚𝐦𝐞𝐫𝐚: Up to 4 cameras can be connected to 1 monitor. Refer to the manual point 7.6, switch to camera scan mode, transitions to a different camera every 10 seconds, keep an eye on your baby· 𝐅𝐞𝐚𝐭𝐮𝐫𝐞𝐬 𝐑𝐞𝐦𝐨𝐭𝐞 𝐏𝐚𝐧/𝐓𝐢𝐥𝐭/𝐙𝐨𝐨𝐦: Night vision, remote thermometer. Contact the sellers to ensure get a compatible camera.· 𝐁𝐚𝐛𝐲 𝐌𝐨𝐧𝐢𝐭𝐨𝐫 𝐂𝐚𝐦𝐞𝐫𝐚𝐬: You can use the HB6550 baby monitor with 2 cameras, 3 cameras or even 4 cameras. Be sure to contact the seller for the right camera.· 𝘼𝙩𝙩𝙚𝙣𝙩𝙞𝙤𝙣: The only one that fits is the HB6550 2021/2022 version. Then you could use HB6550 baby monitor with 2 cameras, 3 cameras or 4 cameras.