Photographer’s Notes: ГОСТ 3634-61 — standard GOST 3634-61 БЧЛЗ — soviet builder BChLZ ГК — «городская канализация», city sewer Л — «лёгкий», light
Vuori Susi’s Notes: БЧЛЗ - BChLZ, old mane of the bilder БКМЗлит (BKMZlit). The old trademark of the plant has the letters B and Z inscribed in the pennant. Year: between 1962 and 1973