Abstract: The invention provides an improved multi-part adapter for use with an input apparatus such as a game controller. The input apparatus is shaped to be held in both hands of a user and comprises an outer case having a front face, a top face and a rear face opposing the front face. A control is located on the top face in a position to be operated by a user's index finger. A thumb stick is located on the front face and positioned to be operated by a thumb of the use. The adapter comprises a first part configured to removably couple to a top of the thumb stick, and a second part configured to removably attach to the first part in a manner that applies force to the first part and secures the first part to the thumb stick.