Tetra 32 Cal./8mm Brass Core Bronze Brush SPECIFICATIONS CA PROP 65: YES CLEANING CALIBERS & GAUGES: .32 CAL, 8MM CLEANING ITEM TYPE: BRUSHES MATERIAL: BRONZE DESCRIPTION Tightly Wound Precision Brass Core Brushes Effectively Remove Fouling from Gun Barrels Features: Industry standard 8-32 male thread (5-40 for .17 Cal. & .204 Cal.) 5/16-27 male thread (12, 20, 28 & 410 Gauge) Close tolerance specifications for perfect bore fit Will not harm or scratch steel Durable and reusable