Hand Grip Strengthener – Product modeling

This was a quick challenge for the RhinoNerd group on Facebook. Consists in modeling a product, in this case, a Hand Grip Strengthener based on a reference of the web.  

Adjustable Hand Grip  Flawless Fitness – Reference

Making a quick research for references, I found the same product under several brands. Such as Sunvp, Flawless Fitness and Exo Trinity Sports, and also some without brand at all, like a generic product.
The main search was to determine the internal components as well as different close-ups to see the details better.
I had no luck about the internal components, studying it a bit, I found a  way about how its adjustable strength works.
 I found some details like overall sizes and also the material of each handle which is POM.

Hand Grip Strengthener
Hand Grip Strengthener Exto Trinity Sports

Having few images and product details I start the modeling trying to get some measures and then the main shapes.

Main curves and dims
Final Model – Hand Grip Strengthener

once then, a few renders trying to imitate the surface finish of the real product as well as the label area which have different surface finish. 

The modelĀ  is available for freeĀ  in my grabcad profile