Bore Tech understands the need for premiumquality nylon brushes, which is whythey have constructed these "double wound"Proof-Positive Nylon Brushes that featuresuperior construction and materials. These brusheshave twice as many bristles as competing brands todouble the scrubbing action and shorten the cleaning process.Features oversized bristles for added strength, and non-brass cores andcouplers that prevent the appearance of copper fouling remaining in yourbores. The .17 and .20 caliber rifle brushes are 1'''' shorter in length toreduce the force needed to push the brush through and prevent barreldamage. For best results use Proof-Positive Nylon Brushes with fast actingcopper cle Mfg: Bore Tech