IPad M1 4K@120hz via TB to HDMI 2.1 adapter

this is all Apple says:

iPad Air 5th gen

Video Recording

• 4K video recording at 24 fps, 25 fps, 30 fps or 60 fps
• 1080p HD video recording at 25 fps, 30 fps or 60 fps
• 720p HD video recording at 30 fps
• Slo‑mo video support for 1080p at 120 fps or 240 fps
• Time-lapse video with stabilisation
• Extended dynamic range for video up to 30 fps
• Cinematic video stabilisation (4K, 1080p and 720p)
• Continuous autofocus video
• Playback zoom
• Video formats captured: HEVC and H.264

Display Support

Supports full native resolution on the built-in display at millions of colours

• Supports one external display with up to 6K resolution at 60Hz

Digital video output

• Native DisplayPort output over USB‑C
• VGA, HDMI and DVI output supported using adapters (sold separately)

Video mirroring

• Up to 4K AirPlay for mirroring, photos and video out to Apple TV (2nd generation or later) or AirPlay 2–enabled smart TV
• Video mirroring and video out support through USB‑C Digital AV Multiport Adapter and USB‑C VGA Multiport Adapter (adapters sold separately)

Video Playback

• Supported formats include HEVC and H.264
• Supports Dolby Vision and HDR10 content