Question 1

HOW TO GET OPTIONAL 3.5" TO 2.5" HDD/SSD TRAY?

Accepted Answer

This case come with 1qty 2.5" mounting bracket. It is located at the very bottom of the other drive bays. It has two posts on one side and you use two screws on the other side. If you are looking for more than 1qty 2.5" drive bay, you will need to purchase an adapter. Many 2.5" SSD drived come with the needed adapter but be sure to check the description first. 
I hope you find this information helpful.

Question 2

How 3.5" total drives can fit in this case?

Accepted Answer

There is one mounting spot behind the power button. You can also fit two more next to the front USB & audio ports though heat issues may arise as those two would be right on top of each other. You could also get 5.25" drive bay brackets to put another 3.5" drive in one of the 5.25" bays.

In general, I love this case and use it all the time. Very easy to use and very good quality with a nice, quiet power supply.

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