You've got a 40-Piece Combination Socket Wrench Set by the brand AIWA.

This is a versatile, entry-level tool kit designed for general household, motorcycle, and automotive maintenance. The "Combination" part means it includes both metric (millimeters) and S.A.E. (Society of Automotive Engineers, or imperial/inch) sizes, which is handy if you work on a variety of things.

Key Components

While the exact socket sizes can vary slightly by batch, a typical 40-piece set like this generally includes:

1. Ratchets and Drives:
2. One 3/8" Drive Reversible Ratchet Handle (the main wrench).
3. One 1/4" Drive Spinner Handle (like a screwdriver handle with a socket drive).
4. An Extension Bar (usually 3" long) for reaching recessed bolts.
5. A 1/4" to 3/8" Drive Adapter to use different size sockets with the main ratchet.
6. Sockets:
7. A large assortment of 1/4" drive sockets in both Metric (e.g., 4mm to 13mm) and S.A.E. (e.g., 5/32" to 9/16").
8. A few 3/8" drive sockets in both Metric and S.A.E. for larger fasteners (including a spark plug socket).
9. Storage:
10. All pieces are contained in a sturdy plastic blow-molded case for organization and easy transport.

In short, it's a fundamental, multi-purpose kit that covers most common nut and bolt sizes you'd encounter for small repairs.

Would you like to know the typical uses for a tool set like this?