Its supposed to be medical grade silicone,i had issues with certain poses you can feel the steel skeleton putting pressure on the elbows in certain positions, but you should be able to feel if its going to be a problem and correct the pose.
Putting the M34 to good use for my Frazzeta Conan custom. It won't be done any time soon but the most important part which is hair and paint have been accounted for. Though I like the M35 for the leg definition the M34 has a better upper body for Conan in books. Then the M35 which is more for Arnold.