The AER MK II single drivers are a more expensive version of the AER MKI drivers. The AER MKII offer a smoother, more detailed, and dynamic sound. The drivers are installed in a FS Acousta back-loaded horn cabinets made with cabinet grade mahogany veneered ¾ “ plywood. Cardas speaker posts are used. This speaker is a very similar to the Lamhorn 1.8s.
I am including links to the reviews of the Lamhorn 1.8 speakers as they are very similar to mine. I am attaching an image depicting the back-loaded design of the FS Acousta cabinets. The cabinets were made by an amateur furniture maker.
Lamhorn 1.8 - http://www.6moons.com/audioreviews/lamhorn/18.html
Shipping information is for one speaker.