If you make gels, electrolyte concentrate, or your own fuel mix, a small refillable soft flask lets runners carry several servings without juggling sachets. Here's what to specify when sourcing a custom gel flask.
Capacity
Gel flasks are small by design. The 150–250ml range holds several gel servings or a concentrated mix and still tucks into a vest pocket or belt. Our capacity guide covers how this compares to standard running sizes.
Mouth Width Matters
Gels and powders are the reason mouth width matters. A narrow neck makes filling slow and messy and traps residue that's hard to rinse out. Specify a wider mouth so the flask is easy to fill with thick gel or powder and easy to clean between uses.
Valve and Flow
Thick liquid behaves differently from water, so confirm the valve and flow are suited to your product's viscosity. A valve that works for water can be frustrating with a heavy gel. Test this on a sample with your actual product, not just water.
Material and Branding
Use food-grade TPU that's BPA- and PVC-free, with reports for your market. The flask also doubles as packaging-on-the-move, so your logo earns repeated exposure every time a runner refuels — see logo printing for methods and durability.
Next Steps
This is one application within the broader soft flask sourcing process. The R50044 is offered in gel-friendly small sizes with a choice of mouth and valve — send us your product details and we'll recommend a spec and sample it with your gel.
