The DRS4DL is a 19" 4kW dome.
In addition to a smaller size the differences are as follows:
It does not require the PSU017 power supply. It connects directly to your power source.
It does not support an ARPA function.
It is fixed at 24RPM so dual range is not available.
By eliminating some features that not all customers utilize we are able to lower cost on the dome (to be announced) and save the consumer money by not having to buy the separate power supply.
It is due to be released in a few weeks. Stay Tuned.