SFP28 (Small Form-factor Pluggable 28) is a type of transceiver module used for high-speed data transmission. It is designed to support 10 Gigabit Ethernet (10GbE) and 25 Gigabit Ethernet (25GbE) applications. It is a compact, hot-pluggable module that is used to connect a network device to a fiber-optic or copper network. It is designed to be used in data centers, enterprise networks, and other high-speed applications. SFP28 offers improved power efficiency, lower latency, and higher data rates compared to its predecessor, SFP+. It is also backward compatible with SFP+ and can be used in existing networks.