The Bussmann FWH 125 AMP Semiconductor Fuse is a type of electrical fuse specifically designed for use with semiconductors. It is rated at 125 amps and is manufactured by Bussmann, a division of Eaton Corporation. This fuse is used to protect semiconductor devices such as diodes, transistors, and thyristors from overcurrent and short-circuit conditions. It is designed to open the circuit quickly in the event of an overcurrent condition, preventing damage to the semiconductor device and ensuring the safety of the system.