0.25A 250V Glass Fuse 5x20 mm

 5x20 glass fuses are small, cylindrical fuses used to protect electrical and electronic circuits from overcurrent conditions. They are named after their dimensions: 5 mm diameter and 20 mm length. Inside the transparent glass tube, a metal wire or strip melts when the current exceeds a specified limit, breaking the circuit and preventing damage to equipment. 

General Features:
 

Size: 5 mm diameter x 20 mm length
Body Material: Clear glass (internal element visible)
Internal Element: Melting wire or strip
Rated Current: Typically available from 0.05A up to 15A
Rated Voltage: 250V AC or 125V AC (depending on model)
Fast-blow: Quickly interrupts the circuit during sudden overcurrent
Slow-blow (Time-delay): Withstands short-duration current surges before opening 

Applications: 

Electronic devices (TVs, power supplies, audio systems)
Industrial control panels
Chargers and small household appliances
Medical and laboratory equipment 

Advantages:  
 

Space-saving due to compact size
Easy to replace
Visual inspection possible (through the clear glass tube)
Cost-effective protection solution

Installation: 
 

Installed using fuse holders or fuse clips
Some versions are suitable for PCB (Printed Circuit Board) mounting