The two-way communication capability of this type of device is actually its audio feature. However, nowadays, the majority of this type of device comes with a two-way voice com or an intercom feature. If you have chosen the one with intercom feature, you can go further and check the quality of audio. If you are not really particular about the sound quality, you can go for the more affordable models. But if you want excellent audio quality, you should also be prepared to spend some cash.