You are ordering one seal for the 3L sausage filler from Sydney based Australian seller. 

The seal fits plunger with diameter 140mm

This silicone sausage filler seal / O-Ring / gasket is used for 3L, 5L, and 7L sausage fillers both vertical and horizontal designs with the plunger diameter 140mm.

ROVTEX brand provides only high quality food processing equipment, parts and accessories.

Replacing a silicone seal on your sausage filler is a straightforward process. 

To watch how-to video, search for "How to fit new silicone seal to your sausage filler"