TOPProductsAccessories/FusesF0305 Accessories/Fuses Glass tube fuse F0305 Glass tube fuse0.5A/250V Φ6.3×30㎜ Applicable model SP21 (S/N: < 09120405001)/CD800a (S/N: < 3082675) SP20 * S/N (=serial number) is located on the back side of product.