This video explains the main functions and practical uses of the heavy-duty electrofusion branch saddle with underclamp in a clear, step-by-step format. Watch a full installation walkthrough on DN90–250 PE100 mains, see how the bolted underclamp provides visual proof of clamping during fusion, and learn how the 4mm automatic pin reads welding parameters. We demonstrate 90–125mm large-bore outlet connections for gas, water, mining and irrigation networks, plus fusion and cooling times, pressure ratings and traceability features.