We don't give out free trial or demo units but there are two ways to test the ZED and ZED Mini camera:
30-day Return Policy
Products do come with a 30 day return policy so if you purchase a camera and decide that it doesn't fit your needs, you can return it for a full refund (excluding shipping costs).
There is also another solution for you to test the ZED SDK without having a physical ZED. You can indeed download and install the ZED SDK and use recorded sequences of the ZED to test it:
1. Download the ZED SDK and install it: https://www.stereolabs.com/developers/
2. Download an SVO file from the following list: https://www.stereolabs.com/download_327af3/SVO_samples/
3. Open the Depth Viewer Tool (C:\Program Files (x86)\ZED SDK\tools) or ZEDfu (C:\Program Files (x86)\ZED SDK\app\ZEDfu) and select Input->SVO to open the recorded sequences.
4. You can use the top-right settings icon to customize the parameters.