Eelink case studies present representative application scenarios for cold chain and asset tracking hardware, showing how a white-label ODM partner supports IoT platform brands across the cold chain. Three scenarios map to Eelink's core focus areas. Scenario one covers shipment-level cold chain evidence: cargo-level multi-sensor trackers combining temperature, humidity, light, shock, and location to produce audit-ready evidence for pharmaceutical and food shipments, supporting FSMA 204 and EU GDP requirements with NIST-traceable calibration. Scenario two covers refrigerated fleet monitoring: cellular trackers with external temperature probes monitoring reefer trailers and refrigerated containers at fleet scale for real-time cold cargo visibility and excursion alerts. Scenario three covers high-value asset and vehicle tracking: long-life concealed GPS trackers with geofence intelligence for mobile assets and large vehicle fleets. Eelink is a 20-year white-label hardware ODM with dual factories in China and Vietnam, monthly capacity exceeding 500,000 units, serving second-tier challengers including regional 3PLs, pharmaceutical logistics startups, smart-label entrants, and IoT platforms that have software but need a dedicated hardware partner. All hardware is white-label with custom firmware, sensor configuration, connectivity options spanning LTE-M, NB-IoT, 2G, and 5G RedCap, protocol integration, and branding.