We built this sleek indoor heater around a 400V, 2500W halogen quartz tube. The whole idea was simple: give you intense radiant heat in a small package, without having to rewire the whole plant. Here’s the thing—running on 400V keeps the current lower, so your wiring stays manageable and you don’t have to overthink the contactors. And that 2500W? It packs the kind of heat density you need for fast, pinpoint warmth. At just 300mm long and 10mm across, the tube focuses the heat into a tight spot. So you get energy where you want it, and you don’t waste it heating up everything around. The halogen tech does a neat trick—it redeposits tungsten back onto the filament, which keeps output steady and stretches the life of the element. The quartz tube can take the heat, too, and it shrugs off sudden temperature swings. Then there’s the R7s connector. It’s a two-pin design that’s proven, quick to lock in, and stays reliable even when you’re swapping it in and out again and again. This setup is for engineers who need a heater that jumps into existing fixtures and gets to work. It heats on demand, with no lag. And that focused beam makes thermal management in enclosed spaces way less fuss. Just keep this in mind: the heat is intense. You’ll need proper airflow and a little breathing room around components. If you’re sealing the enclosure, plan for heat extraction up front—otherwise, the parts nearby will feel it.