I don't have problems threading needles at all, I just figured if I could make it any easier/faster for myself then I would enjoy the process more. I'm very grateful I added this tool to my order because I can honestly see myself using this for all needle threading in my future. I can't tell much difference between the small and large size, the wire is only slightly thicker- but it is clearly indicated which side is where by a small or large raised bump on that edge.