Littelfuse 229/230 Series Slo-Blo fuses are designed for overcurrent protection in a variety of applications, particularly within the telecom industry. Available in both axial lead and cartridge configurations, these fuses combine conventional overcurrent protection with the ability to withstand high current, short-duration pulses. They meet UL 1459 requirements for telephone equipment and offer a unique indicating feature that visually confirms when the fuse has opened, simplifying troubleshooting and improving safety. The fuses are constructed with a glass body and nickel-plated brass fuse caps, ensuring durability and reliability in demanding environments.