Hello
I have an SW3700 which should use SH30 replacement shaving heads. However, SH50 shaving heads also work well on this device (tried it myself). I also have an S5250 on which SH30 shaving heads work well. In my opinion, SH50 should work.
This from the official Philips site:
https://www.philips.co.uk/c-p...
"Fits product type
Shaver Series 5000 (S5xxx)
AquaTouch (S5xxx, AT8xx, AT7xx)
PowerTouch (PT8xx, PT7xx)
Shaver Series 6000 (S6xxx)
HQ71xx, HQ72xx, HQ73xx, HQ77xx, HQ78xx, HQ88xx"
so yes it should also fit the AT750