Peak+ improves on the original Peak's specs with double the RAM at 1GB, but share the same chips in the shape of the 1.2Ghz Snapdragon S4 processor, an eight-megapixel rear and two-megapixel front camera, 4GB of memory and 4.3-inch screen.
It does however, according to Geeksphone, have a "superior look and feel" and "premium materials".
While the Peak+ also runs Firefox OS 1.1, Mozilla is at pains to point out it's not an official Firefox OS handset.
"Today, Geeksphone announced the pre-sale of a new device based on Boot to Gecko technology. We want to clarify that this new phone that was announced is based on Boot to Gecko technology with pre-release software, but is not a certified or supported Firefox OS device," the company said.
The Peak+ is priced at €149 during the preorder period (it's expected to go up to a standard price later on) and will ship in mid September. The original Peak, released in April, was also priced at €149. It sold out shortly after it went on sale.
Firefox OS devices first went on sale to the public earlier this month in both Spain and Madrid, where local operators began selling Alcatel-made Firefox OS devices.
Germany and Greece are expected to be the next countries to get Firefox OS handsets.