Note this size refers to a British Standard Pipe Thread.
This washer fits OVER a 3/4 inch male BSP thread, the washer itself does not measure 3/4 inch.
The inside diameter of the washer measures approx 29mm on the scale of a ruler.
Manufactured from low density polythene.
** BSP thread sizes are measured a special way - have a look at our information page for more details **