Granite Signals Corp. manufactures drone detection systems for prisons and correctional facilities using radio frequency location technology. The company focuses solely on corrections agencies and produces military-grade, export-controlled technology.
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Millennium Access Control Technology, IncMillennium Access Control Technology makes patented access-control systems for jails, prisons, and other secure institutions, with its PACS designed to limit direct contact between correctional staff and violent inmates. Invented by T. Alexander and refined through client feedback, the American-made system has been used in more than 200 correctional facilities, including federal medical centers and major county jail systems. The company also produces high-security equipment such as TV enclosures and a five-way multigym.DIX HILLS, NY
DeTekion Security Systems, IncDeTekion Security Systems, Inc. manufactures perimeter intrusion detection systems and perimeter security products. It also designs, installs, commissions, and trains clients on turnkey outdoor security systems for correctional, energy, defense, military, and industrial applications.VESTAL, NY
On the Gate, LLCOn the Gate, LLC develops and manufactures the patented High-Security Anti-Splash System, a retrofit for jail and detention-center cell-door food slots that helps protect correctional staff from inmate assaults. Founded by David Reisender, the company draws on more than 30 years of correctional law-enforcement experience, including senior leadership and warden experience at New York City Corrections and Rikers Island. The system is proudly made in the USA and features a one-handed, pneumatically assisted door with a removable clear polycarbonate box offering a 280-degree view.GREENFIELD PARK, NY
SentrycsFounded by communications and radio-frequency experts in 2017, Sentrycs develops counter-drone systems that passively detect, track and identify unauthorized drones, then mitigate them without jamming. Its modular platform is tailored to dense urban airspace and sensitive sites, with autonomous fixed, portable and vehicle-mounted deployments. Sentrycs became part of Ondas Holdings in November 2025.NEW YORK, NY