WesTech GAC contactors can be supplied in an open-top gravity system or, more commonly, in pressure vessels. They are typically designed with a conical underdrain for convenient GAC replacement.
By contrast, the HomePod is essentially an extension of the iPhone, like an accessory. When someone asks the HomePod to open a third-party app, the request wonât go directly to the cloud, as with the Echo, but to an iPhone. As a result, developers can't write apps for the HomePod. They must create tweaked versions of existing iPhone apps.
The HomePod is set to cost $350 and will be available in the United States, United Kingdom, and Australia starting in December, with further international rollout following in 2018. The new Airplay 2 functionality will hit the market with iOS 11 this fall.