Up for sale I have a used Factron Quattro iPhone 4&4S case.  I have included pictures with a phone in the case, however the phone is NOT included in this auction.  For sale is the "A7075" version as you can see by the checked box in the picture.  This case originally retailed for over $300! and is one of, if not the most durable case on the market for your iPhone.  Below is some brief wordage from their product page. 

The stylish design of this marque is special.  
By our original design, this protects iPhone4 from shocks or impacts. The shock absorber sheet is included inside of a jacket. 
This "super-elasticity elastomer" has has 5 times more impact absorbing ability,compare with a common silicone sheet.

Lens exchange system 
You can enjoy photography with the lens exchange system which able to change a lens freely, just like a single-lens reflex camera. Options are the close-up lens to the fish eye, and many other options.

Material 
The main part of a jacket can be chosen from two materials. 

Duralumin A2017

Super extra duralumin A7075

A7075 has the highest intensity in an aluminum alloy, and hardness,which surface is also stronger and tenacious compared to A2017.A7075 is a material of the usual FACTRON products. 

Weight : About 62g
Body material : Super extra duralumin (at your choice)
Screw material :Stainless steel 

Please feel free to contact me with any questions.

Thanks for looking!