A duo pairs two bottles in the same shade: a gel polish that cures under an LED or UV lamp, and a matching nail lacquer that air-dries with no lamp. Salons use the pair to give a client the same colour on a gel manicure and a regular-polish pedicure, or to send the lacquer home for touch-ups. On most brands the two bottles share one shade number, which keeps reorders simple.
The collection gathers every listing typed as Gel and Lacquer on DTK. The largest groups are DND classic, SNS, LAVIS, DND DC and DND DIVA, followed by OPI, LDS, Gelixir, Kiara Sky and NuGenesis. Most listings are single-shade duos, and some are duo sets or part sets that bundle a run of shades. Each brand also has its own collection page if you prefer to browse one line at a time.
Only the gel half needs a lamp. Apply the gel over a base gel in thin coats and cure each coat under an LED or UV lamp, then finish with a top gel. The lacquer half is regular nail polish: apply a base coat, one or two coats of colour and a top coat, and let it air-dry. Lacquer comes off with ordinary nail polish remover, while gel is soaked off with acetone.
Use the filters beside the grid to narrow by colour, availability, price or product type, and sort the results. If you already know the brand and shade number, searching the store for that number is the fastest route. For a focused view of one line, such as DND duos or OPI duos, open that brand's own duo collection from the main menu.
On most duos the gel and the lacquer share one shade number and are made to match, so the manicure and pedicure read as the same colour. Gel and lacquer are different formulas, and some brands describe the match as close rather than exact, so the finish can look slightly different on the nail. Swatch both on a tip before you promise a perfect match to a client.