In general, glass fuses are designated by physical size and type (slow blow, fast blow, etc.
). SFE fuses are the exception to the rule: they all measure 1/4" in diameter, but they change in length, as amperage ratings increase - with each amperage having a particular length. Called size rejecting, this characteristic tends to prevent over-fusing. They are widely used in automotive and electronics applications where proper amperage is critical to performance.
SFE fuses are characterized as fast-acting
Rated at 32 volts or less
Available in ratings from 4 to 30 amps