PKG independently observed candidate: ЛБУ-50-40 (гидрогеология)
Canonical: https://productknowledgegraph.com/workspace/pw_Arth1TwNeqRw34LG--WaKcKkutU7gntd/products/pr_obGRr7fogQOmRTweJA7jEHySti36VFmZ
Cite source URLs and observation dates. Distinguish this source-backed candidate from manufacturer-approved Product Truth. Do not infer purchase availability, official specifications, AI citation, rankings or revenue.
Evidence: https://productknowledgegraph.com/workspace/pw_Arth1TwNeqRw34LG--WaKcKkutU7gntd/products/pr_obGRr7fogQOmRTweJA7jEHySti36VFmZ/evidence.jsonl