I read multiple reviews prior to buying this product. But I had an expensive pair of Shoes I purchased while in Scotland. The leather thick and stiff, meant to last a lifetime. Was able to successfully and easily stretch both width and length for a nice comfortable fit. I didn't pre-treat, just left the shoe stand for 2 days  with stretcher installed. Checked fit, adjusted and let stand 1 more days. Repeated process for the second shoe, which had slightly different needs. First set width turning T-handle (increase width clockwise), then adjust length using sliver knob (increase length counter clockwise).
Simple to use. Effective. Did a second pair for minor width stretch. Now on third pair.