Dahon Multifunctional Fold Bike Dropper Inner Pump Folding Bicycle Seat Post 33.9*580/33.9/510mm Small Wheel Air Pump Seat Tube - AliExpress
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Pump bicycle tires with your seat: BioLogic PostPump 2.0
How to usethe DAHON PostPump | Some of our bikes come with a pump integrated right into the seatpost. Here's how it works: #foldingbike #cycling #freedomunfolds | By Dahon Folding Bikes | Facebook
Folding Bike Accessories by DAHON: PostPump - Bicycle Pump in a Seatpost - YouTube