Electronic Systems Technology (EST) designs and manufactures the ESTeem line of industrial wireless modems and transceivers, which create cable-free data communication links between industrial control systems, networked equipment, and mobile devices in harsh environments. EST's target customers operate water and wastewater treatment facilities, oil and gas operations, mining sites, and industrial automation systems, where standard commercial wireless hardware typically fails due to extreme temperatures, moisture, and vibration. EST sells nine ESTeem modem models spanning 150 MHz to 5.8 GHz. Legacy narrow-band models operate at lower frequencies, offer ranges up to 15 miles, and require FCC licensing. The newer Horizon Series broadband models operate at higher frequencies with data rates up to 300 Mbps and are the focus of EST's ongoing R&D. EST also resells antennas, power supplies, and cable assemblies, and offers professional services including site surveys and custom engineering. EST's business model is transactional hardware sales — no long-term contracts — supplemented by professional services. EST outsources sub-assembly manufacturing to contract manufacturers. EST goes to market through direct sales, sales representatives, resellers, and system integrators, with a notable 30-year relationship with Rockwell Automation's Technology Partner Program providing access to a large industrial automation customer base. With only 8 full-time employees and modest annual R&D spending, EST is a small, niche operation serving specific industrial verticals.