This indicator is specifically intended to warn of propellant leaks. One half circle on the disc turns gray when exposed to mixed amine fuel (hydrazine) fumes. The other half turns bright yellow when exposed to nitric acid fumes. These indicators do NOT sense hydrocarbon based fumes.

Intended for thin wall container mounting applications, the standard item is supplied with all necessary mounting hardware. There are many variants on the standard item that have already been produced as well.

Marked with the date of manufacture, these propellant leak indicators have a two-year shelf life.