This is a Swab-Its Foam Swab known as the Gun-Tips, model 81-9001.
Gun-tips are a strong and durable replacement for cotton swabs that do not leave lint and fibers behind. They are flexible enough to round corners" but strong enough to resist breaking. Gun-tips are also washable and reusable. The 5" Large Surface swabs are especially effective for mag wells" dust covers" slides" AR lower and upper receivers" trigger assemblies and bolt carrier assemblies.
Features:
Washable and Reusable
Lint-Free and Fiber-Free
Each Tip Can Be Used Multiple Times