Replacement parts for the Willow Go include flanges, duckbill valves, and pump diaphragms. They are sold individually and as replacement kits or multi‑piece packs.
Willow Go flanges are offered in 21 mm, 24 mm, and 27 mm sizes. The 24 mm flange is noted as compatible with sizing inserts for smaller measurements.
Product details recommend replacing Willow Go replacement parts every 3 months for optimal performance.
The duckbill valves (food‑grade silicone) direct milk flow so milk moves away from the breast and into collection, while the silicone diaphragm helps create and maintain suction and prevents milk from backing up into the pump.
Packaging varies by part and listing: some replacement parts are sold as single pieces, while others are offered in 2‑packs or multi‑piece kits. Check the specific product listing for exact piece counts.
The flanges are described as clear colored to improve nipple visibility and help with correct alignment and placement for effective suction.