Non-rewireable fuse-links (formerly Type A) for use in plugs and socket-outlet adaptors to BS 546 for two-wire a.c. or d.c. circuits up to 250 volts. Current ratings, performance, dimensions, marking, type tests (including the testing enclosure for duty tests). The requirements for Type B fuse-links previously included in BS 646:1935 have been superseded by BS 2950:1958.