In 2005 - 2006, I used the FST ProVision unsure if it's the microstep mentioned here. The ProVision came in two SKU's and could be not only trimmed for flex but also low, mid, high trajectory. The ProVision was marketed to the custom clubbuilder/fitter. I used a lot of them. I know some of those sets of irons are still in use. The ProVision was my first use of FEMCO/FST and one of the reasons I still use FST. Their quality back then was the best of any steel golf shaft manufacturer and is still high today.