It fits under the bar extremely well. It is about 12 inches high, and at full, uninhibited power it moves at about 8-9 mph. It works extremely well as a defender since at the beginning of autonomous, it can just shoot back, knock the other guy out of track (if they are using a timing code), and sit there and defend whatever. It can also push extremely well. I, who weigh about 150 lbs, sat in an empty trash can and it pushed me around without any problems. It climbs like no other. We put different objects in front of it, including 2x4s and 4x4s, it it went over them like that were not even there. I find it to be fairly decent for us being a rookie team. As for protection, all sides are covered by 1/4" lexan except for one, which is coved by about 1/2" of solid aluminum.
-Kesich