Lejek

Lejek is a conical or truncated-conical vessel with a wide opening at one end and a narrow stem at the other, designed to guide liquids, powders, or other substances into containers with small openings. The term is Polish for the funnel, and the device is widely used in households, laboratories, and industry to improve pouring control and reduce spills.

Funnels are made from metal, plastic, glass, or ceramic. They vary in diameter and stem length and may include features such as a filter or sieve integrated into the wide end, or a removable spout. Materials are chosen for chemical resistance, heat tolerance, and ease of cleaning. Some funnels are designed for hot liquids; others are intended for dry powders.

Common uses: In everyday use, a kitchen funnel helps pour liquids or powders into bottles, jars, or oil cans without spilling. In laboratories, funnels support filtration (with filter paper) and sample transfer. Specialized variants include Büchner funnel, used with vacuum filtration, and separatory funnel, a pear-shaped glass vessel with a stopcock used for liquid–liquid extraction.

In marketing and business contexts, the term funnel describes a process that narrows a broad audience down to a smaller number of customers. A marketing or sales funnel includes stages such as awareness, interest, consideration, and conversion, and is used to analyze conversion rates and optimize engagement, lead generation, and revenue.