Fuse reducers allow a smaller fuse to be installed in a fuse block intended for a larger fuse. Reducers fit into most panels or switches including the Dead-front type. Strong contact is maintained both mechanically and electrically. There are no reducers to go from 250V to 600V or 600V to 250V. There are no reducers for switching from one Class to another. There are no reducers for Class T fuses. By design Class L fuses do not require reducers.