This head has 2 positioning pins at 0°、90°、270° (Diagonal direction), please follow the steps below to operate when need to position at 3 angles above：
Locking nut (1), and remove positioning pin. (Loosen the nut (1), and the positioning pin can be knocked tight.)
Loosen nut (2). (The angle can be rotated with just loosening a little bit, and do NOT remove the nut.)
Rotating the head to the angle desired of processing.
Move back positioning pins and press tightly by hand, and lock a little bit the nut (2) to be fit with machine, then knock tightly with tool, and lock tightly nut (2). (Please lock tightly with diagonal way.) (About 25kgf-m.)
PS:
Please remove the foreign body or dirt completely in the hole when using positioning pin, and the positioning precision will be influenced by the foreign body or dirt in the hole.
Positioning pin have to plug in the correct hole site, or will make the bad machining accuracy.