store-us.gl-inet.com OK but bad packaging
I ordered four GL-AR300M16-Ext's twice from Amazon and sent them back because the packaging showed the model with internal antennas and I ordered the model with external antennas. I didn't open the package because of concerns about returning them if wrong. I eventually ordered them from store-us.gl-inet.com and opened the package to find the correct model inside.
I've never seen a product that had a detailed photo on the package that didn't match the model inside. At least you could add a sticker indicating "external antennas" if you want to save money by using a single package for all models.
By the way, the mini-router is well designed and has a great interface. I am working with support on an issue with one of the four new units that drops its wifi link frequently without reconnecting, and support has been responsive so far.