MJ Arsenal's Hydros proved mini dab rigs could be serious. 5 inches it still holds enough water for real filtration, and the geometry is engineered so you get flavor before cloud — the vapor path is short enough that heat hasn't degraded terpenes, long enough that the water has cooled it. Percolation runs through a stemmed downtube that diffuses vapor through the water column.
The chamber takes a full dab without overflow, with walls thick enough to handle thermal shock and consistent glass thickness throughout — no thin bottlenecks. At $52 it's entry-level water-filtered dabs that doesn't feel like a compromise.