Blue Silicone Grouphead Gasket (8.5mm)
De Vecchi Giuseppe brand Blue Silicone Grouphead Gasket 8.5mm. Please note that it is best not to use sharp objects to install as the silicon will tear. An extra-thick 8.5 mm silicone group gasket for many espresso machines.
E61 groupheads vary slightly from manufacturer to manufacturer and your particular model may take anywhere from 8mm to 9mm. New machines with tight tolerances may take 8mm SKU #1051.