Foster 501 Sofa. is made by Brand Walter Knoll. Details and photos of Foster 501 Sofa. are displayed above. You can also check other products in Furnishings category. Brand Walter Knoll / Furnishings Furnishings products by Brand Walter Knoll 369 Armchair. Together Corner Bench. Jaan 780 Armchair. Seito Table. CEOO Conference Table. FK Lounge Chair.