They fit fine
Only 4 stars because I've only used them a few weeks, and I can't measure the closeness of the shave but seems about same as Norelco 8150XL, my older model that uses HQ9 head.  Brand name replacements too expensive now.  These off-brand replacements fit right, allow you put pressure against your skin for closer smooth shave, without grinding or pulling.  Satisfied so far.
Rating: 4 stars