# Bottomless portafilters, and which one fits your machine > What a bottomless (naked) portafilter is, why it's the best tool for diagnosing channeling, and which one fits your espresso machine — cited to manufacturer sources. Source: https://espressofit.com/guides/bottomless-portafilters/ --- A bottomless (or "naked") portafilter has had its spout and base cut away, leaving the bare underside of the basket exposed. It brews into your cup exactly like a normal portafilter — but because you can see the coffee leave the basket, it turns the machine into a diagnostic tool. It is the single cheapest, most useful upgrade for learning to pull a better shot, which is why "bottomless portafilter for [machine]" is one of the most common espresso searches. Below is what it actually tells you, and the manufacturer-verified option for each machine in our database. ## What a bottomless portafilter tells you Watch the underside during extraction. A good shot starts as separate droplets across the whole basket, merges into one glossy, straw-coloured stream, and stays centred. The faults are just as legible: - **Side spray or squirting** — the puck is channeling; water has found an easy path and is racing through one spot, under- extracting the rest. Usually a distribution or tamp problem. - **A jet from one hole early** — uneven dose or a low spot in the puck. - **Fast, pale, gushing flow** — grind too coarse or dose too low; **slow dark dripping** — too fine or too much. None of this is visible through a spouted portafilter, which hides the basket behind the spout. That feedback loop — pull, watch, adjust grind and distribution, pull again — is how you dial in a grinder. ## Which bottomless portafilter fits your machine A portafilter is sized to your machine and does not cross sizes — a 58mm naked portafilter will not lock into a 54mm Breville, and vice versa (see [portafilter sizes explained](https://espressofit.com/guides/portafilter-sizes/)). These are the maker's own bottomless options we've verified: - [Breville Naked Portafilter 54mm](https://espressofit.com/parts/breville-naked-portafilter-54mm/) (54mm) — fits [Breville Barista Express](https://espressofit.com/machines/breville-barista-express/), [Breville Barista Express Impress](https://espressofit.com/machines/breville-barista-express-impress/), [Breville Bambino](https://espressofit.com/machines/breville-bambino/), [Breville Bambino Plus](https://espressofit.com/machines/breville-bambino-plus/), [Breville Barista Pro](https://espressofit.com/machines/breville-barista-pro/), [Breville Barista Touch](https://espressofit.com/machines/breville-barista-touch/), [Breville Barista Touch Impress](https://espressofit.com/machines/breville-barista-touch-impress/), [Breville Duo Temp Pro](https://espressofit.com/machines/breville-duo-temp-pro/), [Breville Infuser](https://espressofit.com/machines/breville-infuser/). - [Breville Naked Portafilter 58mm](https://espressofit.com/parts/breville-naked-portafilter-58mm/) (58mm) — fits [Breville Dual Boiler](https://espressofit.com/machines/breville-dual-boiler/), [Breville Oracle](https://espressofit.com/machines/breville-oracle/), [Breville Oracle Touch](https://espressofit.com/machines/breville-oracle-touch/), [Breville Oracle Jet](https://espressofit.com/machines/breville-oracle-jet/), [Breville Oracle Dual Boiler](https://espressofit.com/machines/breville-oracle-dual-boiler/). - [De'Longhi DLSC085 Bottomless Portafilter](https://espressofit.com/parts/delonghi-dlsc085-bottomless-portafilter/) (51mm) — fits [De'Longhi Dedica Maestro Plus (EC950M)](https://espressofit.com/machines/delonghi-dedica-maestro-plus/). - [Gaggia Bottomless Filter-holder (ashwood handle)](https://espressofit.com/parts/gaggia-bottomless-portafilter/) (58mm) — fits [Gaggia Classic Pro (E24)](https://espressofit.com/machines/gaggia-classic-pro/), [Gaggia Classic GT](https://espressofit.com/machines/gaggia-classic-gt/). - [La Marzocco Convertible Portafilter](https://espressofit.com/parts/la-marzocco-convertible-portafilter/) (58mm) — fits [La Marzocco Linea Mini](https://espressofit.com/machines/la-marzocco-linea-mini/), [La Marzocco Linea Micra](https://espressofit.com/machines/la-marzocco-linea-micra/), [La Marzocco GS3](https://espressofit.com/machines/la-marzocco-gs3/). - [La Pavoni Fascino Bottomless Filter Holder (lever, LPABOTBC01)](https://espressofit.com/parts/la-pavoni-fascino-bottomless-lever/) — fits [La Pavoni Europiccola Lusso](https://espressofit.com/machines/la-pavoni-europiccola-lusso/), [La Pavoni Professional Lusso](https://espressofit.com/machines/la-pavoni-professional-lusso/), [La Pavoni Stradivari Lusso](https://espressofit.com/machines/la-pavoni-stradivari-lusso/), [La Pavoni Esperto Abile](https://espressofit.com/machines/la-pavoni-esperto-abile/). - [Lelit LELIT57 Bottomless Filterholder (PLA570S, classic handle)](https://espressofit.com/parts/lelit-lelit57-bottomless-filterholder/) (57mm) — fits [Lelit Anna (PL41TEM)](https://espressofit.com/machines/lelit-anna/). - [Lelit LELIT58 Bottomless Filterholder (walnut handle)](https://espressofit.com/parts/lelit-lelit58-bottomless-filterholder/) (58mm) — fits [Lelit Bianca (PL162T)](https://espressofit.com/machines/lelit-bianca/), [Lelit MaraX (PL62X)](https://espressofit.com/machines/lelit-marax/), [Lelit Elizabeth (PL92T)](https://espressofit.com/machines/lelit-elizabeth/), [Lelit Victoria (PL91T)](https://espressofit.com/machines/lelit-victoria/), [Lelit Kate (PL82T)](https://espressofit.com/machines/lelit-kate/). ## 58mm machines without a maker's own naked portafilter Some 58mm machines don't have a manufacturer-branded bottomless portafilter — but because they use the 58mm commercial standard, any well-made 58mm bottomless portafilter fits them (match the 58mm size and you're set). In our database that currently includes [ECM Estetika](https://espressofit.com/machines/ecm-estetika/), [ECM Mechanika MAX II](https://espressofit.com/machines/ecm-mechanika-max-ii/), [Flair 58](https://espressofit.com/machines/flair-58/), [Rancilio Silvia](https://espressofit.com/machines/rancilio-silvia/), [Rancilio Silvia Pro](https://espressofit.com/machines/rancilio-silvia-pro/), [Rancilio Silvia Pro X](https://espressofit.com/machines/rancilio-silvia-pro-x/), [Rocket Espresso Appartamento](https://espressofit.com/machines/rocket-appartamento/), [Rocket Espresso Epica](https://espressofit.com/machines/rocket-epica/), [Rocket Espresso Giotto Fast](https://espressofit.com/machines/rocket-giotto/), [Rocket Espresso Mozzafiato Fast](https://espressofit.com/machines/rocket-mozzafiato/), [Rocket Espresso Porta Via](https://espressofit.com/machines/rocket-porta-via/), [Rocket Espresso R Nine One](https://espressofit.com/machines/rocket-r-nine-one/). We only list options a manufacturer states firsthand, so we don't cross-reference a third-party naked portafilter to these until the maker (or the portafilter's maker) names the machine. ## How we verify Every fitment above comes from a manufacturer's own page, read firsthand and quoted on the part's entry. See [how we verify compatibility](https://espressofit.com/methodology/). --- From EspressoFit — a sourced espresso parts compatibility database. Every fitment claim on this site cites the manufacturer page it was verified against, with the date it was read. See https://espressofit.com/methodology/