Cap and Flap: Ader Error and Birkenstock Reunite for Two New Takes on the Boston Clog

Published August 5, 2026 at 8:30 PM

Quick Facts

The Ader Error x Birkenstock Boston Cap features a double-stacked leather panel on the tongue of the slip-on silhouette
On the Boston Flap, Ader Error folds over an elongated version of the traditional Boston tongue panel
The Ader Error x Birkenstock Boston Collection will be released August 6, 2026

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Ader Error x Birkenstock Boston Collection

Everyone is getting into the clog game. Following an industry-wide obsession with loafers and ballet flats, the latest sneaker brand love affair lands us at clogs, with brands from Nike and adidas to Saucony and Asics getting in on the open-back mule trend. For Birkenstock, though, the clog is not a trend; it’s the entire thing.

Ader Error Brings a Flap and a Cap to the Boston Clog

The Ader Error x Birkenstock Boston collection is the second partnership between the Seoul-based fashion brand and Birkenstock. This time, the brands bring two new versions of the classic Boston clog in two colorways each, connecting the collection through a uniting theme of thread, with string stitching together the concept across all four pairs.

The Ader Error x Birkenstock Boston Cap features a double-stacked leather panel on the tongue of the slip-on silhouette, with the forefoot strap slipping through the second suede stack and thick thread securing it. On the Boston Flap, Ader Error folds over an elongated version of the traditional Boston tongue panel, with more thick thread holding it down and the forefoot strap threaded between it. The Cap arrives in Camel and Black suede, while the Flap is dropping in Honey yellow and Blue.

Ader Error x Birkenstock Boston Collection Release Details

The Ader Error x Birkenstock Boston Collection will be released August 6, 2026 through Ader Error, Birkenstock, and select retailers in-store and online. Available in unisex sizing, the retail prices are set at $370 for the Flap pairs and still TBD for the Cap colorways. To keep up with all the latest Birkenstock collab news and drop info, download the Sole Retriever App.