Drone Pad

Drone pads house the drones that build your base buildings. Each pod contains one drone and cannot be upgraded. To acquire more drones, build more drone pads. It is recommended that you save up your green crystals for them, as they will help you build your base faster, as well as reduce upgrade and build times.

At the third, you get a -5% on construction price At the fourth, you add a -10% on construction time At the fifth, you add a -20% on research time

So if you own all 5 drones, you have :
 * -5% construction price,
 * -10% construction time,
 * -20% on research time

and you can build or research 5 things at the time.