Anything from 22" and larger will be fine. For sale are these fully functional, refurbished LCD flatscreen monitors. Available in 15", 17", 19", 20", 22", 23", 24" sizes and supplied with an HDMI adapter.
eBay
BEISHI Dual Monitor Stand Full Adjustable Monitor Desk Mount Swivel Vesa Bracket with C Clamp for 13 to 32 Inch Computer Screens
Aliexpress UK
Ports: VGA, BNC, USB, HDMI, AV input, DC 12V. This product has 4 kinds of input mode (HDMI, VGA, AV1, AV2), or a cable connection, press the AV1 / AV2 button, Switching input mode and a corresponding mode.
eBay
BEISHI Single Monitor Bracket for 13-32in adjustable Monitor holder Universal Computer screen load 2-9kg Gas SpringTV stand
Aliexpress UK
You can connect CVBS security device by BNC port, this monitor is a good choice for your CCTV monitoring system. HDMI support format: 480i (60Hz), 480p (60Hz), 576i (50Hz), 576p (50Hz), 720p (50 / 60Hz).
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Screen Top Storage Shelfs Adjustable Computer Monitors Desktop Screen Top Storage Rack Routers Shelfs Rack Home Organizers
Aliexpress UK
1 Portable Monitor. Compatible for the Thunderbolts Phone and Laptop via TYPE C connection. If can not light up the screen, need extra power on the screen. 5V-3A adapter to connect the screen via the Type C to USB cable.
eBay
Triple Screen Computer Monitor Mount for 13-27 In Screen Multi-Monitor Mount with Tilt Swivel Multiple Monitor Stand VESA 75/100
Aliexpress UK
eBay
NB G40 G45 Gas Spring Arm 22-40 inch Curved Arc Screen Desktop Monitor Holder 360 Rotate Monitor Mount Arm
Aliexpress UK
1x VGA conection Cable(& or adaptors to DVI, USB-C, HDMI or displayport). NO native HDMI PORT : This monitordoes not have an HDMI port. Condition: Fully tested and 100% functional. Screens are clear and in good condition.
eBay
NB G60 Mechanical Spring Arm 27-45 Inch Curved Arc Screen Desktop Monitor Holder 5-16kgs Ultra Wide Monitor Mount with USB Port
Aliexpress UK
Automatic sleep function reducing energy costs and conserving energy. 【Very extensive use 】: This small portable monitor provides a rich set of video input options - including 1x HDMI port for Raspberry Pi, DSLR, PC or other devices with HDMI port use.
eBay
nb NEW F160 gas spring 10"-27" double monitor desktop stand Holder 2-9kg dual arms 360 rotate Computer screen
Aliexpress UK
Ports: VGA, BNC, USB, HDMI, AV input, DC 12V. This product has 4 kinds of input mode (HDMI, VGA, AV1, AV2), or a cable connection, press the AV1 / AV2 button, Switching input mode and a corresponding mode.
eBay
Dual Monitor Stand Holds Up To 19.8lbs Monitor Desk Mount Expandable Display Bracket for 13 To 32 Inch Computer Screens
Aliexpress UK