It is quite overpriced wind synth (and midi controller), with wireless capability.

Note that company tells you

Regarding your comment about no bluetooth functionality in the Sylphyo, we chose not to include bluetooth connectivity because it is generally slow, unreliable and has poor range. Instead, the proprietary wireless technology that connects the Sylphyo with the Link receiver has a range of more than 20 metres, a latency of less than 1ms and is very reliable.

Problem is that here they openly lie.

Inside we have this:

BT832XE is a Bluetooth 5 module with nRF52832, SKY66112 power amplifier,.

Yup, just quite standard wireless Bluetooth board with RF amplifier.

So, this:

Is extremely expensive bluetooth adapter inside, if you need it only to connect to computer :-)

Otherwise it has other things, but for 99% of users it'll be just for bluetooth.