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.
The single-shot basket in IMS’s B68 series — the Ø68-border line IMS assigns
to Gaggia (alongside Carimali and La Cimbali). At 24.5mm deep with a perforated
area of just Ø30mm, it is built to keep resistance up under a small dose:
IMS rates it 7.5–9.5g for a dark roast, rising to 9.5–12g for a light one.
The 253 holes are hexagonally arranged and circular with a conical cross
section — the shape IMS’s competition line is built around, tapering through
the basket floor so flow accelerates rather than stalls at the exit.
Pair it with the 2-cup B682TH24.5M if you
pull both singles and doubles. Note the geometry difference from the B70 line:
the border is Ø68mm rather than Ø70mm, which is precisely why IMS keys Gaggia to
this series. Verified against IMS’s official product page and Competition
catalogue.
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.
What size portafilter is the IMS B68 Competition 1 Cup H24.5 (B681TH24.5E) for?
It is a 58mm basket, 24.5mm deep, for 58mm portafilters.
Is the IMS B68 Competition 1 Cup H24.5 (B681TH24.5E) pressurized?
No — it is a non-pressurized (single-wall) basket, for freshly ground coffee.
Does the IMS B68 Competition 1 Cup H24.5 (B681TH24.5E) 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 B68 Competition 1 Cup H24.5 (B681TH24.5E) fit?
Gaggia Classic GT; Gaggia Classic Pro (E24) — each confirmed against manufacturer sources (listed below).
Sources
https://www.imsfiltri.com/filters/B681TH24.5E.html(archived) — Official IMS Filtri product page ('B681TH24.5E FILTER BASKET', Competition Series, 1 Cup), read firsthand 2026-07-26. Specs verbatim: 'Border: Ø 68 mm', 'Body: Ø 60 mm', 'Height: 24.5 mm', tamper 'Ø 58 mm', '253 holes in hexagonal pattern', holes 'Circular with conical cross section', over a 'Ø 30 mm area optimized for 1-cup flow'. Capacity 7.5/9.5 gr (dark roasted), 8/10 gr (medium), 9.5/12 gr (light). Amazon listing verified firsthand 2026-08-03: 'IMS B681TH24.5E PRECISION FILTER 1 CUP 6/9 g H24.5' — the B681TH24.5E code in the listing title matches this entry exactly. Add-to-cart present, i.e. actually buyable, at the time of checking.
https://www.imsfiltri.com/IMS-competition-Catalogue.pdf(archived) — Official IMS Competition Series catalogue, read firsthand 2026-07-04. Its B68 series heading reads 'B68 (BORDER Ø 68 mm) CARIMALI, GAGGIA, LA CIMBALI' — IMS assigns Gaggia to the B68 series (Ø68 border), not the Ø70 B70 series, which is why B68 baskets cross-reference the Gaggia machines here.