Motorcycle Custom Brass Oil Gauge for Chopper / Bobber Oil Tank Bag - Sight Glass Window - FRENCHED STEEL Bung KIT - Large Barrel Everything you need to mount to your STEEL oil bag! KIT INCLUDES ONE SIGHT WINDOW AND ONE BUNG Brass Sight Window - 1/8" male NPT - 5-5/16" Overall Height with a 4-1/8" Window "FRENCHED" Steel Stepped Bung - Counterbored to give your sight window more of a flush-mounted look. (No more dropping your bungs in your tank during installation). Polypropylene balls are used to help reduce leakage in the event that your bike is leaned over to the point that oil is able to flow past the breather. Please keep in mind that in order for this gauge to read your oil level properly, it must be equip with a breather. Therefore you must make sure to mount your gauge so that the breather is positioned ABOVE the oil level at its highest point. INSTALLATION NOTE: Keep in mind to account for the way the bike leans when resting on the kick stand We also offer a smaller kit with a 3-5/16" sight window as well as kits with aluminum bungs.