The 3-prong rotating Adapter Base helps attach a lamination onto a transfemoral socket. It allows pyramid adapters or receivers to rotate 360 degrees. You can use this with models 1215T, 1225 T/S, or 1216T/S. The 1221S is made from a combination of forged and machined stainless steel, making it strong and lightweight. It has a 2-year warranty and weighs 116g, with a weight limit of 136kg or 300 lbs.