TYN058RG is a Thyristor transistor designed and manufactured by STMicroelectronics. It is a three-terminal, gate-controlled rectifier switch that can be used in controlling the flow of electricity between two points in an electric circuit. It is rated to handle up to 800V and can switch a large amount of current. The device is housed in a TO-225AA package, with a lead pitch of 4mm. It is suitable for use in power supplies, DC motors, and high-voltage switching applications.