Power without compromise. The Hollis fin blends graceful movement, power, and bulletproof construction. Meet the new standard in diving. High grade, heavy duty rubber construction angled strap mounts for comfort and a better transition of power spring heel straps with easy-grip heel tab multiple strap mounting positions for a fine tuned fit vented blade to reduce stress while accelerating water over the blade generous foot pocket james lapenta ?? ymca instructor & padi dive master the f1??s are well thought out, well designed, and very well made. For both my recreational and technical dives, these are the last fins I will ever need Edmund grant ?? wreck diver / parole officer I got my Hollis fins yesterday and dove with them at Dutch springs today. They were very comfortable and I was able to do all variations of kicks with them. This appears to be the last fin I will buy.