EspressoFit

IMS B70 Competition 2 Cup H28.5 M Pattern (B702TH28.5M)

verified · 21 August 2026
Border Ø 70mmTamper Ø 58mm28.5mmBody Ø 60mm
Cross-section to scale, from the dimensions IMS publishes for this basket. The border is what seats in the portafilter — not the tamper figure the size is usually quoted by. See why “58mm” isn’t one standard.

That model name is an IMS product code — series, cup count, height and hole pattern are all encoded in it. IMS basket codes, decoded explains how to read one, and lists every code covered here.

This basket is one of a line. See every IMS B70 Competition basket compared — the whole ladder of heights and variants on one page, with the three diameters they share.

Fits these machines

The deepest basket in IMS’s ridged M-pattern B70 line — 28.5mm, rated 20–22 g for a dark roast and up to 26 g for a light one, which is about as much coffee as a 58mm double will take.

Ridged, and why that matters here

Unlike IMS’s convex and NanoQuartz B70 lines, the M-pattern baskets are ridged — IMS gives the ridge as an external Ø60.5mm. That lip is what the portafilter’s retaining spring grips, so this is the line to choose if you use a spouted portafilter and want the basket held positively in place. On a bottomless holder the ridge does nothing useful, and the ridgeless convex line is the better match.

The M pattern

641 holes of 0.30mm, circular with a conical cross-section, arranged in IMS’s M pattern within a Ø44mm area on a Ø49mm perforated face. The conical section is the detail that matters: each hole widens on the way out, so flow accelerates through the floor rather than stalling at the exit.

Heights in the M series

Code Height Dark Medium Light
B702TH22.5M 22.5mm 13.5/15.5 g 14.5/16.5 g 17/19.5 g
B702TH24.5M 24.5mm 16/18 g 17/19 g 20/22.5 g
B702TH26.5M 26.5mm 18/20 g 19/21 g 22/24 g
B702TH28.5M 28.5mm 20/22 g 21/23 g 24/26 g

Pick by dose. Note how far roast level moves the figure — the same basket takes several grams more of a light roast than a dark one, because lighter beans are less dense.

Same official B70 compatibility as the rest of the series. Gaggia machines take the narrower B68 series and are deliberately not cross-referenced.

Find the IMS B70 Competition 2 Cup H28.5 M Pattern (B702TH28.5M) on Amazon (affiliate link — see our disclosure)

Also fits the same machines

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.

FAQ

What size portafilter is the IMS B70 Competition 2 Cup H28.5 M Pattern (B702TH28.5M) for?
It is a 58mm basket, 28.5mm deep, for 58mm portafilters.
Is the IMS B70 Competition 2 Cup H28.5 M Pattern (B702TH28.5M) pressurized?
No — it is a non-pressurized (single-wall) basket, for freshly ground coffee.
Does the IMS B70 Competition 2 Cup H28.5 M Pattern (B702TH28.5M) fit 54mm machines like the Breville Barista Express?
No. It is a 58mm basket, so it does not fit Breville's 54mm machines or any 54mm portafilter.
Which machines does the IMS B70 Competition 2 Cup H28.5 M Pattern (B702TH28.5M) fit?
Breville Oracle; ECM Estetika; ECM Mechanika MAX II; Flair 58; La Marzocco GS3; La Marzocco Linea Micra; La Marzocco Linea Mini; Lelit Bianca (PL162T); Lelit Elizabeth (PL92T); Lelit Kate (PL82T); Lelit MaraX (PL62X); Lelit Victoria (PL91T); Rancilio Silvia; Rancilio Silvia Pro; Rancilio Silvia Pro X; Rocket Espresso Appartamento; Rocket Espresso Epica; Rocket Espresso Giotto Fast; Rocket Espresso Mozzafiato Fast; Rocket Espresso Porta Via; Rocket Espresso R Nine One — each confirmed against manufacturer sources (listed below).

Sources

Spot an error? The fastest fix is the source itself —send us the manufacturer page that contradicts this entry and we'll correct it and cite it. See how we verify.