Luminous Effect: Made with special glow in the dark yarn! You only need to fully expose the yarn to sunlight for 15–30 minutes to fully absorb light, then place it in the dark, and you will be pleasantly surprised. Different Colors: The package contains 5 skeins of glow in the dark crochet yarn, glowing in the dark, meeting your crafting and replacement needs. Different colored yarns have varying sensitivity to light in the dark, with white being the most noticeable. Specifications: Polyester fiber, 1 skein 50g/1.76oz, 5 skeins totaling 260g/9oz, length 250m/273yd, suitable for beginners using 2.5–3mm crochet hooks.