Multi-fins was a Byron Bay, Australia, company that specialised in moulded fins.
Started in the early 1980s, and closed sometime before 2000.
They supplied their own fin-boxes, in the standard Bahne design, and an eclectic range of surfboard fins from large single fins to symmetrical/asymmetrical foiled fins for Thrusters.
By the early-1990s their surfboard fin range was severely threatened with the spread of the much lighter FCS plug and fins.
In addition, by this time sailboard riders' demand for higher performance saw a trend to stiffer laminated fins, the moulded Multi-fins considered "soft" or "spongy."

Also note, for some reason, Australian fin manufacturers invariably locate the tongue (with a hole for the bolt and plate) at the front, but in the US it is usually at the rear of the fin base.