What does the silver in the needles of the Plus Ag version do — is it just marketing, or is there a real difference from ordinary insoles? — Insole "Plus" 5.0 Ag size 37–40 – Lyapko

According to the manufacturer's description, the applicator's materials are iron, copper, nickel, zinc, silver and medical rubber; silver (Ag) is named in the model name. How silver and the other metals affect sensations or results is not stated on the product card, and there is no comparison there with models without silver, so a “real difference” cannot be judged from the description.

The needle pitch is 5.0 and the size is 37–40. If you have sensitive skin or an allergy to metals (the composition includes nickel), start carefully and watch your skin's reaction after each use; if in doubt, consult a specialist (a general recommendation, not a manufacturer's instruction).