All Purpose Security & Surveillance, 6608 Tamarack Dr, Allentown, PA 18104, US

Kastle Systems International is a full-service electronic security and access control system provider that has more than 30 years of experience providing outsourced security services to office buildings and tenants throughout the United States. Founded in 1972 and headquartered in Washington, D.C., the company has 70-percent market share in the Washington, D.C.,-area Class A office building market. An employer of more than 450, Kastle Systems International has operation centers and regional offices in Chicago, Dallas, Houston, Los Angeles, New York, Philadelphia and Sydney, Australia. The company protects in excess of 289 million square feet of commercial office space in more than 1,700 buildings with approximately 37,000 tenant spaces.