This is a "3-in-1 electric socket" that can be used for bolts and nuts of three sizes (17mm, 19mm, and 21mm). It is a tip tool for attaching to electric screwdrivers and rechargeable screwdrivers to work efficiently. It is ideal for construction, scaffolding, civil engineering, electrical work, and plumbing. Across-flat dimensions (mm): 17-19-21 Shaft dimensions (mm): 6.35 (hexagonal shaft) Overall length (mm): 93 Material: Chrome vanadium steel (Cr-V) Weight: 270g Note: A double-ended bit with a total length of 65mm or more is required for installation (double-ended bits are sold separately). ■About the product Brand new, unused. The box may have deteriorated during display or storage. Please check the product photos. ■Orders, Shipping, and Payment Shipping period: We will ship within a maximum of 5 business days (excluding weekends and holidays) after your order is confirmed. Please note that we cannot offer same-day shipping due to cost reduction, so if you are in a hurry, please be aware of this. Damage during shipping: We take great care in packaging, but if there is any damage, please contact us immediately. ■Cancellation, Returns, and Exchanges Customer convenience: We do not accept cancellations, returns, or exchanges after your order has been confirmed. Please understand the product characteristics before purchasing. Initial defects/Damage: In the event of initial defects or damage during shipping, please be sure to contact us before giving a receipt evaluation. After confirmation, we will respond promptly and sincerely (exchange or refund). Please note that we cannot respond after the receipt evaluation. ■Inquiries Response period: Due to cost reduction, we will respond to inquiries within 3 business days (excluding weekends and holidays).