These are Rayan Castella vacuum flasks, likely 1.8L or 2.0L capacity, designed to keep drinks hot or cold for extended periods.
Capacity: Available in sizes such as 1.8L (Castella 70) and potentially 2.0L.
Insulation: Features a vacuum gap and potentially a glass inner chamber to provide 24-36 hours of thermal insulation.
Material: The body is made of safe plastic materials like PP or ABS.
Design: They come with a handle and an integrated cup/lid for serving.