Instant purchase OK. I'm not very familiar with this, but please delete any data if there is any. XBee modules come in various antenna configurations, and this one has an RPSMA connector. You'll need to connect a coaxial cable from an external antenna to this. Therefore, it cannot be used without an antenna. This product has "certification" for legal use in Japan. Please use it with confidence. However, this certification is conditional on using the specified antenna. Connecting a different antenna would require obtaining a new certification. Retail price: 3973 yen Please feel free to comment if you have any questions.