This is the original prism for the F3. It is smaller than the the HP model AND has a bigger view. Why would anyone want an HP? The HP is a longer eye relief, so you can see the whole frame with glasses on. If you do not wear glasses then this is the one that you want. This one is in excellent condition. The only defect is a tiny dent on the film advance side. Otherwise, everything is great and the glass is clean and free of defects.