6688 GE 5 Star used/good (7.2ma)
6688 GE NOS 1966 (9ma)
(!!) (Single) JAN-6688=E180F Philips Holland NOS gold pins 1972 (11ma)
6688=E180F National UK black plate NOS probably made by Amperex (9ma)
6688=E180F National UK gray plate NOS probably made by Amperex (16ma)