Like a yarn needle that you can wear on your finger. The only place I could find one was on Amazon. I was very surprised that my local cross stitch shop didn't sell them. https://www.amazon.com/Yarn-Works-Trolley-Needle-Controller/dp/B001681WJI/ref=mp_s_a_1_2?crid=R039WQCYHYN3&keywords=trolley+needle+laying+tool&qid=1678841269&sprefix=trolley+needle%2Caps%2C353&sr=8-2