Compatibility with flasks
This cap screws onto the Quechua Tritan or Aluminium bottles of the 500 and 900 range of 1L or less (the tube is too short for the large 1.2L and 1.5L sized bottles). It is not compatible with other bottles or water bottles.Inner tube can be cut, using cutting guide provided, to fit different size flasks (from 0.5 L to 1.5 L) .