The Envoy Pro mini features a USB 3.0/USB 3.1 Gen 1 interface. It chieves sustained transfer speeds up to 427MB/second.
The 480GB OWC Envoy Pro mini is priced at $287. and is available now for same day shipping from MacSales.com. The 240GB version costs $194.95 and a 120GB model is $109.75.
OWC is also offering reduced prices on its memory upgrades for the late 2015 27-inch iMac with Retina 5K display. You can get a 64GB memory upgrade kit for only $100 more than the 32GB offering direct from Apple.
Prices range from $63.75 for an 8GB kit (for upgrading to the standard 8GB RAM) to $699 for the 64GB Kit.