Perhaps this was part of an installation kit for a radio?
Along with the inline fuse holder, you'll also receive one Buss AGC 20A, 32V fuse, & one Buss AGC 15A, 32V fuse
Inline waterproof fuseholder for 1/4" x 1-1/4" (6.35 mm x 31.8 mm) fuses.
Accepts #16 to #12 AWG Cu wire
IP67 rating for exposed locations & ideal for harsh environments
Vibration Resistance: Per MIL STD 810C
Temperature Rating (RTI): +100 °C
Brittle Point: Less than -60 °C