The back is hook. The image shows you what you are getting, both how the patch/patches look and the quantity, unless otherwise noted.
Embroidered Paches from Heavy Duty Threads Highest Quality Materials Hook & Loop Backing Made in the USA
Embroidered Patch P FS Embroidery Patch 4X10 and 2X5 Hook on Back Gray
Custom Blank Patches – Create Your Own Blank Embroidered Patches
Square Blank Patch 4 x 4 White Patch w/Black — AllStitch Embroidery Supplies
Custom Blank Patches – Create Your Own Blank Embroidered Patches
Blank Embroidery Patch 10x4 and 5x2 Inches Hook Backing
Embroidered Patch Marshal EMB Patch 4X10 and 2X5 Hook ON Back/Black/Pink : Arts, Crafts & Sewing
Sheriff Negotiator Embroidery Patches 4X10 and 2X5 Hook On Back Gold Letters by HightSeller : Everything Else
Blank Patches for Embroidery - Biker Patches - Velcro Patches
ENFORCEMENT Officer embroidery patches 4x10 and 2x5 hook on back grey
Blank Patches for Embroidering - TheCheapPlace