10Pcs F20AL250V 5X20MM 20A Fast Blow Fuse 20 Amp 250V Glass Quick Blow F20AL Cartridge Fuse Fast-Acting Fuse

Worked perfectly right when I needed it!

I was testing the current output of a battery trickle charger with my multimeter, which means that I had the positive lead plugged into the 10A jack of the meter. I got the information I needed and reminded myself to move the positive lead back to the voltage jack on the meter.I immediately forgot to do this.The next time I tried to measure voltage, I sent full battery current into the 10A circuit of my meter. I heard a very tiny SNAP, indicating that the 10 amp fuse in the meter had done its job and was off to fuse heaven. Oops.The fuses in my meter use a ceramic body and these have a glass body. Ceramic is preferred for working with high energy circuits because the body is less likely to shatter and burst with a high energy pulse, but my little pocket meter won't be hanging out in any industrial control panels any time soon. Some day I'll spring for ceramic fuses but for now these get me up and running again.I wanted to make sure that these fuses were at least marginally close to their rated spec, IE that they wouldn't pop at 500mA or hang on until 100A and roast my meter. I hooked one to a variable power supply and used an amp clamp to monitor current. At 10A (rated spec), the glass body of the fuse began to fill with smoke but the fuse continued to conduct electricity. It hung on until 20A, where it let loose with a pop and a small flash of light. I repeated the experiment with another fuse and got the same results.Typically fuses will carry their rated current for some length of time and will hang on for quite a bit above their rated current before opening. I believe Littelfuse specs some of their standard fuses to last 4 hours at rated current and 300 milliseconds at 275% rated current. The fuses I tested fall right in line with this. No, it's not a rigorous test by any standard, but it tells me that my meter probably won't melt in my hand if I short it across a motorcycle battery (again).I installed one fuse in my meter and tucked the other seven away for the next time I screw up.

They were the right size

Worked great

Fuses for a laptop DC charger. AS SUCH ... I hope to never, ever have to use these spares!!!They look perfect. They arrived perfect. They arrived FAST. IF I had needed them as a replacement rather than spare I would have only had to wait about 20 hours! PERFECT!

As described, and received faster then promised

Right size, right amperage

I’m not sure if they were defective or it was my equipment, but they kept blowing on me. My guess is it was my equipment?