- Butterfly shape nut M3 M4 M5 M6 M8 M10 combination. Metal products are easy to use and durable. - Butterfly shape is designed,more effort.Features two Stainless Steel Butterfly shape wings, one on each side allow for quick installation without tool - This is high quality stainless steel butterfly wing nuts assortment kit, includes 6 most-used sizes: M3 M4 M5 M6 M8 M10 . - Widely used in machinery,chemical industry,construction, electricity, textile, sports equipment,paper,sewage treatment,automotive,medical equipment, chassis circuits, electronic equipment, communication equipment, ships etc.