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