Based on this product's specifications, here are some alternatives and similar models
Tube for liquid cooling Alphacool 18438 — acrylic, diameter 13 mm, length 400 mm, transparent
Summary description:
Acrylic tube for liquid PC cooling systems by Alphacool (model 18438). Made of transparent acrylic glass, with outer diameter 13 mm and length 400 mm, designed to transport cooling liquid within custom loop setups. Suitable for visible tubing in desktop water-cooling, connecting reservoirs, radiators and blocks, offering rigid, clear conduit for coolant flow.