This is a fold-up hex key set, also known as an Allen wrench set.
Function: Used to tighten or loosen bolts and screws with a hexagonal socket head.
Design: The fold-up design offers portability and convenience, allowing the keys to be stored compactly and easily accessed.
Material: Typically made from durable materials like heat-treated chrome vanadium steel for strength and longevity.
Applications: Commonly used for tasks such as bicycle maintenance, assembling furniture, and working on various machinery.