The 1.618 was the second generation release of the Phi. A wide body aluminum yo-yo with polished satin finish aluminum body for low friction, reversible spacers for gap adjustment, weight distribution, take apart design, bearing axle. Slightly narrower than the original Phi.
Each one was numbered. Look at the bottom of the Logo Side View and you will notice the serial number is the first number, followed by the ".618". Pictured is number 15.
