Oil Fill Plug Heavy-duty oil fill plug with large inspection window. This oil fill plug is designed specifically for axle housings and provides easy access for fluid changes and monitoring. The easy-grip design ensures a tight seal while allowing for simple removal during maintenance. The large 1.25" view hole lets you keep an eye on fluid levels and condition without removing the plug. Built from durable aluminum construction with a steel weld-in bung for secure installation. The included O-ring provides a reliable seal to prevent leaks while maintaining easy serviceability for regular maintenance intervals. Key Features Part Number: PN1401 Fitment: axle housings Material: Aluminum plug with steel weld-in bung Dimensions: 1.25" inspection window for fluid monitoring Design: Easy-grip design with O-ring seal What's Included 1x Aluminum fill plug 1x Steel weld-in bung 1x O-ring seal Notes Large 1.25" view hole for easy fluid level monitoring Easy-grip design for tight fit and simple removal Designed specifically for axle housings