Part of the National Bureau of Standards, the Law Enforcement Standards Laboratory (LESL) establishes voluntary law enforcement equipment standards based on actual performance levels of equipment. The standards program is designed to protect law enforcement personnel and to enhance their safety. The standards cover various types of equipment such as helmets, gas masks, body armour, and police emergency vehicle sirens and lights. Standards for police vehicles cover safety as well as performance. LESL also is working on standards for many types of police radio equipment, security systems, and other technical equipment used in law enforcement.