This is a great idea from ADDI, allowing you to weave contrasting yarns into your usual knitting, as you go!
Two beautiful hollow ADDI 8mm nickel-plated needles have a hole near the tip and come with a threader pass a yarn through.
The yarns passed through the needles are automatically woven into your knitting as you work: a simple and effective technique for adding texture and colour to your textiles.

Instruction video