Earlier this week, we got a brief sampler of the explosive additions coming to Trials HD in the "BIG Pack" DLC ... pack. Today, a RedLynx press release has shared a few specifics with us regarding the downloadable content's ... contents. These specifics include how to unlock the pack's three new achievements, a list of some of the new physics objects (car, rocket turbine, gravity field, wind and motor, to name a few), and some of the additions that will come in the simultaneously released title update. You can find these details posted after the jump. RedLynx also sent along a new trailer, which we've posted above. You're going to feel awfully silly when you realize that you've read all this when you could have been watching a dude ride a motorbike in a space station. The BIG Pack is due out next Wednesday, December 23. According to the presser, it will cost 400 -- which is half the price we heard earlier this week. Typo? Or Christmas miracle? We've contacted RedLynx to find out.