These are Nova XT Overmold misprints. They are listed by weight and color. Stamps will vary.
Innova's Nova is their second release using their new overmold technology, which applies the characteristics of certain types of plastics only where needed. The Nova features a stiffer center flight plate for stability, but a tackier rim material to deaden the impact with the basket. These characteristics make for a great putter! And this nice, straight flyer makes it go right where you point it.