JAYO Glow in the Dark PLA Filament, Blue Luminous Effect for Decorative 3D Printer Filament, 1.1kg Spool(2.4lbs), Compatible with Most FDM Printers

Multi-pack bundles are the point — buying 4 or 10 spools at once brings the per-kg cost down sharply compared to individual purchases. Good for anyone running the same color through a lot of prints and watching their material budget.