These work - but they get hot and do not shave terribly well.
I'd hoped to use an old Norelco 725RL electric razor as a spare with new blades.  However, even with a touch of electric shaver lubricant, they run hot and do not shave terribly well.  Not recommended - but might be a little better than a manual razor.  I'll keep it as a backup for now.
Rating: 2 stars