These 250ml soft flasks are constructed from BPA-free thermoplastic polyurethane (TPU), offering a flexible, lightweight hydration option that collapses as you drink. Designed to slot neatly into running vests, hydration packs, or hand-carry during trail runs and hikes, they provide a convenient dual-flask setup out of the box. Note that flask color may shift subtly over time depending on water pH levels.
