Security Instrument

Founded in 1960, Security Instrument Corporation is Delaware's largest full-service independently-owned security company — a privately held organization that has served thousands of customers across Delaware, Maryland, New Jersey, and Pennsylvania for 65 years without ever being acquired, merged, or absorbed into a national chain. With 75+ employees across its Wilmington headquarters and Milton branch, Security Instrument has earned its place on the SDM 100 — the annual ranking of the top 100 security integrators in America — reflecting decades of demonstrated technical capability and client satisfaction that regional competitors rarely achieve and national providers routinely claim without supporting evidence.

Security Instrument's service portfolio delivers the full spectrum of electronic security and life safety integration: professionally engineered system designs, turnkey installation services, 24-hour system monitoring, inspection and testing, emergency service, and UL-certified systems engineered for the most stringent security requirements. The company's consulting discipline — distinguishing itself as an integrator rather than an installer — means that every engagement be