The Mikuni HS42/012 is a replacement round clamp-on air filter element designed for Mikuni HSR42, HSR45, and HSR48 smoothbore carburetors.

Features washable red cotton gauze material with a standard 2.5-inch mounting flange inside diameter.

Specifications & Features
Application: Fits Mikuni HSR-series carburetors used on Harley-Davidson and custom motorcycle applications
Material: Washable and reusable pre-oiled cotton gauze
Flange Diameter: 2.50 inches (Standard HS42/012)