The fuses are true to size and fit my 10 x 38 mm fuse holders. I actually used my DC adjustable power supply to test one to see when it would blow and it blew right as I turned the power up just past one amp. They seem to be effective and rated appropriately.

These ceramic fuses were the exact type and size I needed. They are 1Amp fast blow 500 volt. These are perfect fit and protection for my 100 amp solar charge controller. this fuse protects my charge controller from lightning strikes/surges because this fuse is rated for up to 100,000 amp. Great replacement fuse and also good to have on hand.

Buon prodotto.