877 Series are real 3.6 x 10mm fuses. The more compact footprint was made possible by doing away with conventional over-capping (single pigtail). This series also offer higher I2T values than similar over-capped offerings in the market. 877 series is a Slo-Blo® type fuse, designed in accordance to IEC 60127-3 standard. They are suitable for end applications that are more susceptible to higher frequencies of surges/transients.