"Ball Return" mechanism... what is it?

[Randy_Ai]

I have a question,

what is this "Ball Return" mechanism that is described in section 2.3 of the rules (under Playing Field Construction)?

Where is it located?
How high is it?

[Chris Hibner]

It has been removed, so you don't have to worry about it.

It was basically like a "doggy door" on a garage. An opening about 12 in x 12 in at the bottom of the driver's station so the balls can be passed through it. FIRST has decided to eliminate it from the playing field (see the first team update).