EUC. Requires batteries for soothing vibrating motion. Rocks or has legs that unfold so chair is stationary. This is an awesome chair. Comes with rattle that detaches from chair & overhead mobile that has a rattle & pull the bone & it plays Twinkle Twinkle (teaching cause & effect). It swings out of the way easily to get baby out of the chair, and is also easily detachable. Please see photos. Non smoking home.