ST stands for Straight Tip - a quick release bayonet style connector developed by AT&T. STs were predominant in the late 80s and early 90s. As data centers, telecom networks, and enterprise infrastructures migrate to fiber. Fiber optic connectors play a crucial role in the world of telecommunications and data networking, acting as the critical interface between fiber optic cables and the devices or networks they connect. These connectors are designed to align microscopic glass fibers perfectly to ensure that light. QuickSwitch® 6253 Quad Channel ST Duplex MMF Multi-Mode Fiber Optic A/B Switch with Voltage/Contact Closure Remote QuickSwitch® 6253 Quad Channel ST Duplex A/B Switch with Voltage/Contact Closure Remote allows the user the capability of switching all four channels simultaneously between A and B. L-com's Multimode fiber A/B Network Switches are physical layer hardware solutions which support a variety of switching, or access and control applications all in a compact desktop enclosure. All of these optical switches are purely optical path, there is no optical to electrical to optical conversion.