MECCANIXITY Thread Reducing Nuts Insert M10 x 1mm Male to M6 x 1mm Fine Thread Female Adapters 10mm Long Pipe Fitting Conversion Sleeve Reducer, Pack of 5: Amazon.com: Industrial & Scientific
Slingshot M10 to M6 thread adapter set
Adapter - extention piece - M6 x 1 keg, male - M10 x 1 female - 23 mm, 1,63 €