Based on this product's specifications, here are some alternatives and similar models
BWT W+M Flex straight connector 3/8" — plumbing fitting for water treatment
Summary description:
BWT W+M Flex straight connector 3/8" is a plumbing fitting designed for reliable connection in water treatment systems. The straight 3/8" connection provides a compact link between pipes, filters, or appliances. It suits installation where a direct, low-profile coupling is required for drinking-water treatment, filtration units, or service lines.