The MF-R300 is a PTC resettable fuse designed to protect low-voltage power supplies and loads in electronic equipment. It features a maximum voltage rating of 30 V and a maximum current rating of 40 A, with a hold current (Ihold) of 3.0 A and a trip current (Itrip) of 6.0 A at 23°C. The device has an initial resistance of 0.05 O and a post-trip resistance of 0.08 O maximum, with a maximum time to trip of 10.8 seconds at 23°C and typical tripped power dissipation of 2.00 W. Constructed with radial leads using Sn/Cu material and cured flame-retardant epoxy polymer insulation meeting UL 94V-0 requirements, the MF-R300 is RoHS compliant and halogen-free. It is commonly used in computers, peripherals, and general electronics applications where automatic overcurrent protection and automatic recovery are required.