There's also the ZenFone 2E from AT&T and just the basic ASUS ZenFone 2. We're guessing the latest sibling, the ZenFone 3, will have several variations too but for now, we've got information that the next model will be introduced this coming May complete with a USB Type-C port and a fingerprint scanner.
The information was sourced from a GFX Bench document that says a phone with model number Z010DD features a 5.9-inch screen with 1,280 x 720 resolution display is in the works. The ASUS handset is said to run Android 6.0 Marshmallow but with other less than remarkable specs compared to the older ZenFone 2. Rumored specs include an Snapdragon 615 chipset 3GB RAM, Qualcomm Adreno 405, 32GB storage, 12MP rear camera, 8MP front camera-- lower compared to what a ZenFone 3 variant has.
We're assuming this ASUS Z010DD is just one ZenFone 3 variant. More will be coming with varied specs if we are to base on Asus' pattern in releasing new products last year.