The Nest Pour Over Dripper incorporates double-walled insulation with 304 food-grade stainless steel materials. It is compatible with the VSSL's reusable #1 304 stainless steel mesh filter. The integrated dual threading allows the coffee pour-over dripper to assemble with the Nest System into one compact, transportable unit, or serve as a stand-alone coffee dripper that can simply sit on the top of most mugs.