□ Product Details Anyone can easily thread a needle. With practice, you can tie a thread to a needle in under a minute. Many commonly sold threaders use batteries, but this product is rechargeable and can be charged anywhere with a USB port. You don't need to buy batteries, making it economical. Suitable hook sizes (approximate): Maruseigo 5-14 / Iseni 1-15 / Gre 3-7 / Chinu 1-9 / Madai 7-13 / Kawagi (Speed) 7-8 / Karei 8-16 / Kitsune 0.8-10 / Sode 2-12 / Herasure 2-10. Suitable leader line: Recommended for use with 0.8-4 size thread.