The head screws is made of stainless steel material, durable, strong and no rust. Replace the old or damage part easily. Forehead head screws is compatible with Ninebot ES1 ES2 ES4. Thread Diameter: 5mm, Head Diameter: 9mm, Total Length: 11mm, Allen Hex Drive: 3mm Item Specifications Thread Diameter:5mm Head Diameter:9mm Total Length:11mm Allen Hex Drive:3mm Material:Stainless steel Package 4pcs Head Screws 1x Wrench Mounting Screw Set for Ninebot Max G30 ES] Made of for durable stainless steel, this mounting screw set is specially designed for Ninebot ES1, ES2, ES4, Max G30, and F series electric scooters. [ Material] Crafted with high-quality material, these screws are sturdy and practical, long-lasting use Segway Ninebot Charger ODO LUCK 2PCS External Battery Mounting Screws For Ninebot ES1 ES2 ES4 Scooter Replace Parts Accessories For Segway Ninebot Electric Scooter Trottinette électrique