RF1857-000 is a fast acting, 5.6mm x 20.5mm, radial leaded, high temperature, ultra radial reflex fuse manufactured by Littelfuse. It is UL Recognized, CSA Certified, RoHS and REACH Compliant. It has a voltage rating of 125VAC, a current rating of 0.5A, an interupt rating of 1000A @125VAC, and an operating temperature range of -55°C to +125°C. The dielectric strength of the fuse is 1000V, and the housing is composed of a ceramic body with metal end caps. The RF1857-000 is designed for use for temperature over-load, short circuit, and over-voltage protection in a variety of electronic, automotive, and industrial applications.