A double basket will generally be sized between 14 grams and 21 grams. The double basket usually has straight walls or walls that slightly taper in.
This basket will fit all of the below as it's a standard basket:
ASCASO, AURORA, AZKOYEN, BEZZERA, BFC, BIANCHI, BRASILIA, CMA, CONTI, ECM, ELEKTRA, ESPRESSA, EXPOBAR (CREM), FAEMA, FIAMMA, FIORENZATO , FRACINO, GRIMAC, IBERITAL, LA NUOVA ERA, LA SCALA - SYMPHONY, MAGISTER, MARCFI, MY WAY - GRUPPO IZZO, NUOVA SIMONELLI, PROMAC, RANCILIO, ROYAL, SANREMO, SV ITALIA, VIBIEMME, VFA EXPRES, WEGA
As you probably know the most common basket diameter is 58 mm and is usually the standard size used in commercial and higher-end domestic/prosumer espresso machines. Occasionally you might see a you might encounter 53 mm diameter baskets, and rarer again, the 57 mm basket.
58mm – the most common size used by most brands
57mm – incredibly rare size used by domestic machines brands like Lelit and Ascaso
54mm – used on many domestic machines such as Breville’s Bambino, Bambino Plus, Barista Express, Barista Pro and DeLonghi’s La Specialista Arte
53mm – not as common but used by brands such as La Spaziale, Dalla Corte, some lever-piston machines, and some domestic machines
51mm – used on the smallest form factor machines by domestic appliance brands such Breville, DeLonghi and Krups