The iWi putter is Ping's range of moeveable weight putters. Ping tell us that the ‘smash factor’ or force of impact of the iWi putter is the same as the rest of their range so it is easy to move models and this achievement is commendable. The insert gives very good feel and the sound at impact is the best of any insert putter we have tried, although not as good as a pure all metal putter. The real difference is in the sole where there are 2 steel weights of 12 grams each which can be changed. Ping have raided the tungsten larder and will be selling a separate weights kit with a wrench and a pair of 20 gram and 28 gram tungsten weights so you can adjust the weight of the putter yourself. All this flexibility is great, but we found the standard weights to be heavy enough. However with the weight set costing around a 3rd of the price of the putter itself, this is not a cheap option, but the fact such a kit is available at all is a welcome development none the less.