Bore Tech Nylon Brush (3 pack) Default:30 cal The Redding Competition Shellholder Kit 25 dB protection The Redding Competition Shellholder Kit consists of five shellholders in varying heights with increments of RCBS was founded over 60 years ago and has been producing high quality reloading equipment ever since our premium Proof Positive Nylon Bore Brushes are strongly recommend when using fast acting copper removing cleaners such as our Eliminator Bore Cleaner or Cu+2 Copper Remover This is due to the fact that traditional phosphor bronze brushes contain over 90% copper in their composition and will turn patches blue when in contact with most copper removing cleaners