Could you clarify if you were thinking of a ?

"5773" most likely refers to yarn from the Cascade Heritage line or the Jewish year 5773 (2012–2013).

I used it for a pair of contrast-toe socks, and the stitch definition is crisp. It doesn't split easily while knitting, which is a huge plus for intricate patterns.

If neither of those fits, "5773" also appears in these contexts: