Ping ISI-K irons. Ping's aim with these irons was to combine the accuracy of the Zing 2 model with the shot-making capability of the popular Eye 2. Ping's engineers achieved this goal through extreme perimeter weighting and a patented cavity design that has an ellipse and five vibration-absorbing fingers 'starburst' design. A more rounded shape, a cleaner top line, and alignment markings on the face give the golfer confidence over the ball. The result is a club that feels solid, offers the playability that golfers need to control their shots, and is forgiving on mishits. This 'K' model is the oversize version - with a wide top-line for added confidence at address. First launched in 1996 - Ping ISI-Ks are so popular you can still buy them new from Ping.