# Bill of materials

| Qty | Item | Source / specification | Notes |
| ---: | --- | --- | --- |
| 1 | Center yoke | Printed from `center_yoke.step` | Arm cheek plates, lock guide and hook clevis are one part. |
| 1 | Left shoulder arm | Printed from `left_shoulder_arm.step` | Deep solid beam, captured root and shallow strap notch. |
| 1 | Right shoulder arm | Printed from `right_shoulder_arm.step` | Mirror of left with unique component name. |
| 1 | Folding hook | Printed from `folding_hook.step` | 42 mm rod pocket, 40 mm throat. |
| 1 | Dual positive lock bar | Printed from `dual_positive_lock_bar.step` | Rigid linked blocking member and recessed thumb pad. |
| 2 | Arm shoulder screw | Purchased M5 × 18 mm shoulder-length, low-profile head | Simplified envelope in CAD. Use an unthreaded shoulder through the rotating stack. |
| 1 | Hook shoulder screw | Purchased M5 × 26.25 mm shoulder-length, low-profile head | Simplified envelope in CAD; the shoulder spans the main front cheek and outboard hook clevis. |
| 3 | M5 low-profile prevailing-torque locknut | Purchased | Simplified cylindrical envelope in CAD; production selection must be verified. |
| 2 | Compression spring | Purchased, approximately 3.5 mm OD × 10–12 mm free length | Fits around lock guide pegs and biases the bar to engaged. Not modeled because coil geometry changes under compression. |

All pins and nuts remain captured after assembly. None are removed during folding, deployment or use. Printed pins are deliberately not supplied; if improvised for a prototype, they are prototype-only and not the intended load-bearing hardware.