We already had a pretty good handle on General Dynamics’ ruggedized, Flipstart-like GoBook MR-1, but the company’s now gotten official with it, and is providing a few more specs and clarifications. While the MR-1 shares much in common with the Flipstart, it has gotten a few significant upgrades, including a 1.2GHz Core Solo U1400 processor, some new wireless options (including WWAN by the end of the year), and a hard drive boost to 80GB, with 16GB and 32GB SSD drives also available as an option. Of course, perhaps the most significant upgrade is its newfound ruggedness, which meets or exceeds MIL-STD 810F specifications for temperature, drop, and vibration tests, as well IP-54 specs for dust and humidity. Getting the biggest boost, however, is the device’s price, which will come in a hefty $4,450 when it’s released in September.