Other than removing the cylinder and weighing it, there has never been an easy way to monitor how full a nitrous bottle is. ZEX has remedied that problem by developing the industrys first Nitrous Level Gauge. This gauge displays how much nitrous is left in the bottle with both an illuminated LED indicator and a numerical fill percentage readout. It also accurately measures how much nitrous is being used. The ZEX Nitrous Level Gauge is compatible with any manufacturers nitrous system, and installs with an easy 5-wire hook-up. The gauge can monitor any commonly available nitrous cylinder from 1-30 lbs. and can monitor nitrous systems jetted up to 500 horsepower. The ZEX Nitrous Level Gauge features built-in automatic dimming for night use and is easily reset when refilling the nitrous bottle. An industry-first component; accurately monitors total nitrous system usage including purge. Compatible with any manufacturers nitrous system 5-Wire hook-up makes installation easy Fully configurable for any bottle size or nitrous shot Automatic dimming for night use The part number for this item is Zex 82395