I believe that's a 3/8 allen wrench, but it's a really simple matter to get under the vehicle and try different wrenches on until you find the correct one. Many calipers are held on with a 3/8 allen bolt, but some are 10mm and some even 1/2 regular bolt.
Depending where it was built, a 3/8 Allen key or 15 mm regular wrench.
The front caliper on a 1995 Ram is requires a 3/8 inch Allen wrench to remove the bolts.
7mm Allen wrench
I believe that is a 3/8 Allen.
Allen wrenches come in various sizes. There is no definitive information as to what size is needed to remove a brake caliber so you will need to match the wrench size to the best of your ability.
3/8 inch Allen wrench
The last one of those I worked on was 3/8 Allen key
For a 1999 Dodge Ram 1500 brake job, you'll typically need a 3/8-inch Allen wrench (also known as a hex key) to remove the caliper bolts. However, it's always a good idea to double-check your specific model and configuration, as variations may exist depending on the brake system or aftermarket parts. Make sure to have the necessary tools on hand before starting the job.
Remove the two bolts and use a screwdriver against the hub and caliper.
With a wrench!!
A 3/8 Allen key.
3/8 in.