This is the stock plug for most stock mopeds. Some mopeds like the Morini, and Tomos A55 use the long reach B6ES.
If you have performance modifications, you might want to try a colder plug like a B7HS or B8HS.
When it comes to spark plugs, NGK is the World Leader. Makers of spark plugs for virtually every automotive, motorcycle, marine and small engine application, NGK dominates. NGK Spark Plugs (USA), Inc. was established in 1966 as a subsidiary of NGK Spark Plug Co, Ltd., of Japan. Its purpose was to establish and develop a market in the United States for NGK spark plugs and NTK ceramic products.