A power plunger has several different-sized cup washers available – these are sized for the following applications:
In kitchen and large sinks, showers and floor drains (cup size 1 ½” (4cm), 3 ¼” dome -4 ½” overall (9.5 – 11.5cm).
To unblock toilets (cup size 5 ½” dome – 8″ overall (14- 20cm)…
…and in small hand basins and baths (cup size 1″ (2.5cm), 1 ½” (4cm).
The dome size is the part of the washer that sits inside the drain rim and the overall size covers the drain entrance.
The cup washer attachments come in a few sizes: 1″ (2.5cm), 1 ½” (4cm), 3 ¼” dome -4 ½” overall (9.5 – 11.5cm) and 5 ½” dome – 8″ overall (14- 20cm).
The smaller sized washers are for sitting inside smaller drain holes e.g. in basins (1″ (2.5 cm), 1 ½” (4cm).
The cup washers are reversible. This allows the washers to be used on many different drain sizes, with a bit of trial and error to select the correct size.