Fuse marked GDB what does that means?

A fuse marked "GDB" typically refers to a type of fuse used in electrical systems that is designed to protect against overcurrent. The "G" often indicates that it is a glass tube fuse, while "DB" could refer to its specific rating or application, such as "distribution board." These fuses help prevent damage to electrical circuits by breaking the circuit when the current exceeds a safe level. Always consult the manufacturer's specifications for precise meanings and applications.