Abstract: A filter is provided within a transparent drinking straw. The filter has a dense core region and a less dense outer peripherial region. The filter is retained in place within the straw by frictional forces under static conditions. The frictional forces which maintain the filter in place under static conditions may be overcome by fluid flowing through the straw causing the filter to move within the conduit. The filter may support particulate matter which may be a medication or drug. Accordingly, the device may be used as delivery device for drugs administered by oral ingestion. Movement of the filter from a first to a second position provides a visual indication that a predetemined volume of fluid has passed through the conduit.