Like the already announced Galaxy J1, the J7 and J5 appear to be made out of plastic. The Galaxy J7 is the largest (and also the thinnest) of the bunch, sporting a 5.5-inch 720p TFT display, and measuring 152.4 x 79.2 x 7.9 mm. The J5 offers a 5-inch 720p TFT display, while measuring 142 x 73 x 8.5 mm.
It seems that the J7 and J5 share most of their features, including Android 5.0.2 Lollipop, LTE, 5 MP front-facing cameras, 8 MP rear cameras, 1.5 GB of RAM, and 16 GB of expandable storage space. Both smartphones have octa-core processors (at least according to TENAA), but the J7's CPU is clocked at 1.4 GHz, while the CPU that's powering the J5 is clocked at 1.2 GHz.
The Galaxy J7 and Galaxy J5 that are pictured below (model numbers SM-J7008 and SM-J5008) should soon be released in China, and we expect to see slightly different variations of them in other markets. Of course, we still have to wait for Samsung to announce the new handsets to know where and for how much they're going to be available.
source: TENAA (1), (2)