West Pharmaceutical Services makes the components that hold and deliver injectable drugs — primarily rubber stoppers, seals, plungers, and coatings used to package vials, syringes, and cartridges. West's customers are biologic, pharmaceutical, and generic drug companies, and West sells directly through its own global sales force. West operates two segments: Proprietary Products (~81% of sales) and Contract-Manufactured Products (~19%). Within Proprietary Products, the core business is High-Value Product (HVP) components — highly engineered elastomeric closures and plungers that must be chemically compatible with the specific drug they contact. Key HVP products include NovaPure stoppers and FluroTec-coated components, developed with partner Daikyo. West also makes self-injection devices, drug containment solutions, and administration systems. The Contract Manufacturing segment primarily manufactures auto-injectors and multi-dose pens, with GLP-1 drugs (Ozempic, Wegovy) as a key growth driver. West's business model centers on "spec-in" stickiness: once a West component is specified in a drug's regulatory filing, switching is costly and rare, creating durable recurring revenue. HVP components carry gross margins well above 60%, versus 20–30% for Standard Products, so converting customers from Standard to HVP is the core margin expansion driver. Three secular tailwinds support growth: biologics and biosimilars, GLP-1 drug volume growth, and EU GMP Annex 1 regulations, which require pharmaceutical companies in Europe to upgrade contamination controls, potentially converting billions of existing Standard components to higher-margin HVP products.