West Pharmaceutical Services is based in Pennsylvania, US, and is a key supplier to firms in the pharmaceutical, biotechnology, and generic drug industries. West sells elastomer-based packaging components (including stoppers, seals, and plungers), non-glass containment solutions, and auto-injectors for injectable drugs. The company reports in two segments: proprietary products (about 80% of total revenue) and contract-manufactured products (about 20% of total revenue). It generates approximately 55% of its revenue from international markets and 45% from the United States.