Cheap enough and nice to have when you start work on your manifold.

Throughout the honing process there's going to be many repeated washings of the bore runners. They need to be frequently cleaned to get out grinding media, chips and slurry that comes from the grinding/honing process. Especially important to you guys that don't have a compressor/spray gun to blow out the runners from time to time. Just push or pull a dry brush through it.

These become a "must-have" after polishing as a layer of oil forms that contains fine aluminum powder in it, thickens and clings fast to walls. Without some type of long, cylindrical brush it's impossible to clean as just running soap and water thru a runner wont begin to touch it. Just clean your runners with the bottle brush, dishwashing liquid and hot water. It'll make em sparkle!

These, while not the best quality in the world are effective and do the job for cleaning the intake between steps to be able to visually check your work.

The 3" brush in this kit is no good to us but if purchased elsewhere you'll pay 3-4 times as much for a 7/8" or 1.5" alone than this whole kit costs. I bought 5 of them at my local Harbor Freight store as they are frequently out of stock on these and at this price rather have too many than not enough. Bottle brushes can be purchased at Harbor Freight.