The MF-R400 is a PTC resettable fuse from Bourns' MF-R Series, engineered to protect low-voltage power supplies and loads in computers, peripherals, and general electronics. This radial-leaded device features a cured, flame-retardant epoxy polymer insulating material that meets UL 94V-0 requirements, ensuring reliable performance and safety compliance. The MF-R400 operates at a maximum voltage of 30V and maximum current of 40A, with a hold current of 4.00A and trip current of 8.00A at 23°C. It exhibits an initial resistance of 0.03 Ohms at 23°C and a post-trip resistance of 0.05 Ohms maximum, with a maximum time to trip of 12.7 seconds. The device is RoHS compliant and halogen-free, making it suitable for environmentally conscious applications requiring automatic overcurrent protection without manual intervention.