CAD Design - I need design files only

I’m building a horse-mounted health monitor and I need two small “dummy” housings modelled so I can test how the finished device will sit on the animal before electronics are ready.

There are two TPU-printable pods:
• Design A: 40 × 30 × 9 mm
• Design B: 140 × 22 × 7 mm

Both must contain a ballast cavity so I can add weight, and each needs its own snap-fit cap. The bodies will be curved slightly to follow the horse’s flank and should include simple functional details such as shallow clips or locating tabs to keep them in place during fitting trials. No cosmetic surface replicas are required—just clean, manufacturable geometry that prints reliably in flexible TPU. I will take care of slicing and printing myself, so please focus on sound CAD that respects wall thickness and tolerance guidelines typical for 95 A TPU.

Deliverables
• Native CAD files (SolidWorks, Fusion 360 or similar) with parametric history
• Exported STEP or IGES for each pod and cap
• Watertight STL files ready for 0.4 mm nozzle printing

I’ll verify the design by dry-fitting and loading the cavity; we’re done once the caps hold securely with a reassuring “click” and no visible gaps. Let me know what software you prefer and how quickly you can turn the models around—looking forward to collaborating.