Pro / Cont's:
+ The Nano SIM can be precisely stuck in the adapter, it engages formally
+ When turning and shaking the adapter the Nano SIM will not fall out
+ The adapter together with Nano SIM fits perfectly into the iPhone 4 SIM card slide
- Turning over the slide, the adapter will fall out though is no room between the adapter and slide
Conclusion:
Very good product for a reasonable price.