A puck screen sits on top of the tamped coffee, under the shower screen. It
spreads the arriving water across the whole bed rather than letting it drill in
at one point, and it stops spent grounds being pulled up into the group at the
end of the shot.
IMS’s DS51 is built from an AISI 301 photo-etched membrane with a
150 µm filtering power, pierced by 199 holes of Ø2.4mm. The photo-etching
matters for the same reason it does on IMS’s shower screens: it is one solid
piece, so there are no layers for coffee oils to work into.
One screen, two machine families
This is the unusual case on this site of a single part that IMS names for two
different manufacturers, and it is worth being precise about why.
IMS specifies the DS51 by tamper compatibility — “Compatible with filter
baskets for 51 mm tampers” — rather than by brand. It then names it explicitly
on both of its brand pages:
De’Longhi — “For De’Longhi machines using 51mm filters, the correct puck
screen is the 51mm model (our DS51).”
La Pavoni — “For Pre-Millennium groups, use our DS51 puck screen … For
Post-Millennium, the DS51 is also the correct choice.”
So the cross-references below come from IMS naming each brand directly, not
from us inferring that two similar numbers must be compatible.
A note on La Pavoni’s numbers
La Pavoni’s own machine pages state a “filter holder internal diameter (with
filter)” of 52 mm, while IMS describes post-millennium La Pavoni as taking
“a 51mm basket and tamper”. Both are correct and they describe different
things — the holder measured with the basket in it versus the tamper that fits
inside the basket. The same relationship is set out on the
La Pavoni lever tamper entry, and the
general version of the trap is in
why 58mm isn’t one standard.
Not covered here: IMS notes the DS51 also fits pre-millennium La Pavoni’s
49mm baskets. Vintage pre-millennium levers are a different format and are not
in this database, so no pre-2000 machine is cross-referenced.
On a lever machine specifically, IMS makes a point worth repeating: the screen
“protects the shower screen from being sucked up during the lever lift” — the
upward pull as you raise the lever is exactly when loose grounds migrate.
Other items confirmed to fit machines this one fits — useful if you're kitting out a single setup. The count is how many of those machines overlap; nothing here is a new fitment claim.
It is a 51mm puck screen, for 51mm portafilter machines.
Which machines does the IMS DS51 Puck Diffuser Screen fit?
De'Longhi Dedica Maestro Plus (EC950M); La Pavoni Esperto Abile; La Pavoni Europiccola Lusso; La Pavoni Professional Lusso; La Pavoni Stradivari Lusso — each confirmed against manufacturer sources (listed below).
Sources
https://imsfiltri.com/prodotto/puck-diffuser-screen-ds51/(archived) — Official IMS Filtri product page ('DS51 PUCK SCREEN', Accessories / Puck Diffuser Screen), read firsthand 2026-08-10. Specs verbatim: 'SKU: DS51', 'Tamper Compatibility: 51 mm', 'Hole Dimension: Ø 2.4 mm', 'Number of Holes: 199', 'Filtration: 150 µm'. Described verbatim as 'studied to better distribute the water over the coffee pod, thanks to the new IMS technology that combines a hole area with a 150-micron filtering power photo-etched membrane', 'Constructed in combination with an AISI 301 photo-etched membrane boasting a filtering power of 150 microns', which 'guarantees an impeccably even water distribution over the coffee bed while preventing grounds from flowing back into the shower screen'. Compatibility stated as 'Compatible with filter baskets for 51 mm tampers'.
https://www.imsfiltri.com/la-pavoni-precision-filters-showers.html(archived) — Official IMS La Pavoni compatibility page, read firsthand 2026-08-10. FAQ item 03 states verbatim: 'Can I use a Puck Diffuser Screen with La Pavoni Europiccola? Yes! For Pre-Millennium groups, use our DS51 puck screen (which fits the 49mm baskets perfectly). For Post-Millennium, the DS51 is also the correct choice. Using a puck screen on a lever machine is highly effective: it protects the shower screen from being sucked up during the lever lift and ensures a flawless water dispersion.' The same page states verbatim that 'Post-Millennium machines (built after 2000) have a larger group head and require a 51mm basket and tamper.'
https://www.imsfiltri.com/delonghi-precision-filters-showers.html(archived) — Official IMS De'Longhi compatibility page, read firsthand 2026-08-10. States verbatim: 'Which Puck Diffuser should I use for De'Longhi?' — 'For De'Longhi machines using 51mm filters, the correct puck screen is the 51mm model (our DS51).' The same page states 'Most De'Longhi home machines, including the Dedica EC680/EC685 and EC885, use a 51mm group head.'