Elbow and knee can bend for 120 degrees. A cover is inside the shoulder joint so the joint won't be too exposed when it's pulled outward. The abdomen can be stretched for wider articulation for the torso.
On display in a Japanese hobby store it seems. May be from one of the stops in Tamashii Nation's Super Robot Chogokin Preview Caravan.
* Mazinger Z - August 6th release, 3,675 Yen (inclusive of tax).
* Weapon Set for Super Robot Chogokin Mazinger Z - August 6th release, 1,050 Yen (inclusive of tax).
Images are from Super Robot Chogokin Diary and ToyWorld Forum.