Bambu Lab’s AMS is awesome for multi-material, but it’s also kind of famous for one big weakness: it doesn’t actively dry your filament. In this video I put the Sunlu AMS Heater on the bench—an aftermarket add-on that’s trying to fix that exact problem by bringing real heat-based drying into the AMS ecosystem. I walk through what you actually get, how the install works, and how it fits into a normal workflow where you’re swapping spools, leaving filament loaded, and expecting consistent prints without mystery stringing or surface defects from moisture. I tested it on both the original AMS and the AMS 2 Pro, and I focus on real-world performance and what I’d actually change if I was designing it myself. This unit is pre-production, so I also call out a few quirks and what Sunlu says is expected to improve in the final version. If you’ve been chasing moisture-related print issues—especially with filaments that don’t tolerate humidity—this is the kind of upgrade that can make an AMS setup feel a lot less fragile, but it’s not a magic box and the details matter.