There are five HDBaseT classes. Classes A and Class B refer to Spec 1.0 of the HDBaseT standard, while Classes C-E refer to Spec 2.0. Class A supports the 5Play feature set: ultra-high-definition audio & video, controls, Ethernet, USB and power, over a single 100m/328 ft LAN cable. Class B was created to provide a more cost-effective solution. It does not support the Ethernet functionality, and transmission distances are limited to 70m/230ft.
Class C is the equivalent to Class A for Spec 2.0, supporting all 5Play elements. Class D supports lower resolutions – up to 1080p – and shorter distances (up to 30m/100ft), particularly suitable for classroom designs. Class E supports HDBaseT over a fiber channel, for even longer distances (several kilometers).