The narrow head for the Challenge MS-5 Multi-Spindle Paper Drill is an optional drill head assembly designed to enable closer spacing between drill spindles. When installed, these narrow heads reduce the center-to-center distance between spindles to as little as 1-3/8 inches (35 mm), compared to the standard minimum of 1-7/8 inches (48 mm). This configuration is particularly useful for applications requiring tightly spaced holes, such as drilling medical forms or other specialized documents.