Earin M-2 Earbuds: Upgrade and Miniaturization

Custom TWS Earbuds Prototype - Earin M-2 Miniaturization**

UNIVERSITY PROJECT: Redesign Earin M-2 earbuds SMALLER to reduce ear protrusion.

CURRENT SPECS: 24×15×15mm shell, 4g each, 60mAh battery, 4hr playback, BA driver, NFMI sync, touch controls
TARGET SPECS: <20×13×12mm shell (33% smaller volume)
• Same features or close equivalents
• 1-2 FULLY WORKING prototype pairs

DELIVERABLES REQUIRED:
1. New shell design (3D printed or molded)
2. Custom PCB layout for reduced volume
3. Component sourcing (mini BA driver, BT/NFMI, 40-50mAh battery)
4. Full assembly + functional testing
5. Audio test + TWS pairing validation

I HAVE:
• Complete Earin M-2 teardown photos
• Exact measurements + target dimensions
• Protrusion problem photos
• Clear feature priority list

EXPERIENCE NEEDED:
• Proven TWS earbuds prototypes (post portfolio)
• Micro-soldering + compact PCB experience
• Balanced armature driver integration
• Previous true wireless builds

TIMELINE: 4-8 weeks
LOCATION: Remote OK, UK-based preferred