It's 12 mm bolts, not Allen key.
7mm Allen wrench
You need 3/8 Allen key.
7mm
I believe that will be a 7mm Allen key.
3/8" Allen wrench.
3/8"
3/8" Allen wrench
A 3/8 Allen key.
I believe that's a 5/16 Allen.
On some later model Fords the calipers have 7mm Allen heads, -an unusual size.
You need a 12 mm wrench, not Allen key.
Almost all Kia calipers are held with 14 or 17mm bolts, NOT Allen screws.