Cross-Check™ provides a convenient visual method for identification of vibratory loosening or tampering in nuts, bolts, fasteners, and assemblies. Provides an excellent way to visually check for loosened bolts during Pre and Post flight inspections. Marks will be easily broken if parts are tampered with or become loose. Highly visible marks. Excellent adhesion to metal and other substrates. (1) one oz. tube of Orange Cross Check lasts for several tear downs and rebuilds, as your only using a small amount per bolt.