This is just what I've been looking for. Works great for maintenance oiling in the hard to reach places under rail and in chamber grooves. Also great for applying preservation lubricant to the exterior of weapons with picatinny rails. Have you ever tried to "wipe" your fore rails with a rag??? Yeah, pain in the but. This makes quick easy work of it. Of course you could probably use other household items that would do a similar job, but for the price, it can't be beat to have the right tool for the right job.
Pros: Gets hard to reach spots, reuseable
Cons: Occasional stray loose bristles
This review was written in the old system and had content requirements that are different than reviews written today.