Dolphin Robotic Pool Cleaners by Maytronics are Quality robotic pool cleaners made in isreal and distributed in Australia by Maytronics Australia. 

The X Series Dolphin cleaners is a range designed to be sold by the every reseller except for the Maytronics Dolphin Supreme or Elite Dealers.  This means these particular Dolphin robotic cleaners are sold in a more competitive market and are usually greater value than the similar model in the S-Series and supreme range of Dolphin Cleaners. 

Comparison
The Dolphin X40 is the equivalent model to the Dolphin S300i Robot Cleaner
The Dolphin X30  is the equivalent model to the Dolphin S200 Robot Cleaner
The Dolphin E10 is the equivalent model to the DB1 Robotic Cleaner

You generally won't see these models on the Maytronics Australia website as they try to minimize exposure of other models which may dilute the profitability of cleaners for their Elite dealerships.