In American English, the chin placement represents the vowel phonemes found in the words small, red, and shoe.
The chin placement is located on the vertical midline (neither off to the left nor right) and near the bottom of the chin.
In general, the point of contact is the tip of the longest extended finger of the handshape. In the case of handshape 8, this is not the case. The index finger is the contact finger for the chin placement (e.g., chew, yes) so that the other extended finger (the middle finger) points away from face and does not cause ambiguity as to which placement is being contacted.