A 3-functional, 1000-MW PO/EO hetero polyether polyol made for the production of viscoelastic (VE) PU foam. It is a component polyol mainly to produce MDI-VE foam with superior air flow and exceptional compression set values, allows for cooler sleep while giving comfortable support. Its versatility allows it to be incorporated in combustion-modified viscoelastic foam (CMVE) formulation.