If you are in development phase and need very simple BT module with SPP and URAT and HC-06 is one of the option which might fit.

But you may find that HC-06 size 27*13*2 mm , it is a little big ,and you prefer small size module , we are glad to recommend a small size module ,BT821 .V4.2 Dual Mode ,it is ultra small size :15*12*2.0mm ,and dual mode support SPP/GATT .

If you need a module totally same as HC06 module ,then BT826 it is best choices ,but BT826 it is better than hc06 module ,BT4.2 dual mode SPP+GATT .

We are glad to advice you that we begin to design a module HC 05/HC06 pin to pin .This new module would be totally instead of HC05/HC 06 ,then no need do any change on your pcba.

Feasycom Team