Mock-neck sweater dress Great condition! This is a mock-neck sweater dress with a thigh slit. It's knit with Wonder Yarn — the lightweight yarn that lives up to its name. This peachy-soft yarn offers the all-season warmth of wool, without the wool. It's made with LENZING™ ECOVERO™ Viscose - responsibly sourced wood-based fibres produced through a process that reduces impact on forests, biodiversity and water supply.