The Stern 7 had parallel sides not tapered as in picture, also the male in picture was cast not stamped and never had a latch. The picture is of a PD attachment, not a precision attachment, note the lingual clasp arm which you wouldn't use if it were a precision attachment. I have a few plastic males that were sent from the C&B labs that are a translucent red that might be from Ney or maybe Attachments International (now Implants Direct) talk to Darwin Bagley. The translucent red PD attachments didn't have rounded corners like the other PD's.