Contract not Included
Premium Bandai, Bandai's official shopping website, began offering light-up LED replicas of the Soul Gem and "a certain character" Dark Orb (can't tell because it's a spoiler of the third Movie) from the Puella Magi Madoka Magica the Movie 3: Rebellion for pre-order on Monday.
The set includes interchangeable tops that emulates the magical girls' soul gems as they become more corrupted. This is not the first time Premium Bandai releases something like this. Previously they released light-up Soul Gems and brass Grief Seeds of the TV series (First Two Movies).
The set will retail for 5,400 yen (about US$54) and is scheduled to ship in August, so if you didn't get a chance to grab the the first time this is your chance.
Here's another promotional image, but beware it's a huge spoiler of the third movie so if you haven't watched that movie, don't click on it. Here