Did you get it right?
One modern grooming item appears among older barber shop supplies.

The Answer
The correct answer is: the disposable plastic multi-blade razor guard cartridge.
Here is why
- The towels, strop, mug, brush, tonic bottles, combs, and scissors fit the old barber shop.
- The small disposable plastic razor cartridge is the modern mismatch.
Why people miss it
It is grooming-related, so it blends in even though the material and style are much newer than the room.
What answer did you get before checking?