**Brief Introduction**
SDZ21 light‑weight folding lock targets road‑bike and lightweight‑sport‑bicycle users. Weight‑reduction optimization is implemented while preserving baseline anti‑theft performance for daily commuting to lessen riding‑carried load. Compact folded dimension for direct frame‑mount‑bracket attachment. Key‑operated with attractive cost‑efficiency, suitable for sport‑accessory distribution channels and student‑commuter‑oriented large‑volume orders.

**Material & Craftsmanship**
Weight‑optimized alloy‑steel lock‑segments balancing light‑weight property and baseline security. Scratch‑proof wear‑resistant engineering‑plastic bumper shell. Copper key cylinder. Full‑set frame‑mount‑bracket accessories.

**Key Features**

1. Weight‑optimized construction lowers carried load for weight‑conscious cycling groups.
2. Compact folded footprint with frame‑mount bracket for on‑bike fastening instead of backpack‑storage.
3. Simple stable key‑operated mechanical unlocking.
4. Cost‑competitive mass‑production model with reliable supply.
5. OEM‑ready for custom shell colors, laser‑engraved logos and color‑box packaging.

**Application Scenarios**
Road bicycles, mountain bikes, urban commuter bicycles and student‑use bikes.

**OEM & ODM Service**
Custom laser‑engraved logos, shell colors and packaging. Small‑batch mixed‑order friendly.