The TCL 43S451 is a 43-inch 4-Series 4K UHD HDR LED Smart Roku TV. It features a 3840 x 2160 resolution (UHD) and supports HDR10 and HLG high dynamic range formats. The TV has a 60Hz refresh rate and a viewing angle of 178°/178°. It also includes Roku's smart TV platform with access to thousands of streaming channels. 
Here's a more detailed breakdown of the specs:
Display:
Screen Size: 43 inches (42.5 inches actual)
Resolution: 3840 x 2160 (4K UHD)
Refresh Rate: 60Hz
High Dynamic Range (HDR) Support: HDR10, HLG
Display Colors: 1.07 billion
Viewing Angles: 178°/178° 
Smart Features:
Operating System: Roku TV
Voice Control: Compatible with Siri, Alexa, and Hey Google
Easy Access: Simple, personalized home screen to access cable, antenna, or streaming 
Other Features:
4K Upscaling: Enhances lower resolution content to near 4K quality
Game Mode: Optimizes picture settings for gaming
Inputs: Multiple HDMI ports (4 on some models)
Outputs: 1 USB port 
Measurements:
Dimensions (with stand): 37.7"D x 24"W x 7.3"H
Weight (with stand): 13.9 pounds