Littelfuse FLQ-4 FLQ004, 4Amp 500V Cartridge Fuse Dimension: 0.406" Dia x 1.500" L (10.31mm x 38.10mm) 4 Amp (4A) 500V, Slow Blow, Time Delay, Midget Fuses This FLQ-4 could be used to substitute for Bussmann FNQ-4 and Ferraz Shamwut/Mersen ATQ-4