BoB Jr. is a very tiny bipedal robot based off of many robots before it. "Standing on the shoulders of giants." The interior space inside the head is a 1" cube and he stands no taller than an AA battery. He utilizes very tiny, low voltage servos, a Picaxe 20M2, and various other parts combined with a 3D designed and printed body. I love building tiny robots and he was a fun project all around.