CRJ700s at Delta are operated by regional airlines for Delta. The Delta CRJ700 is branded as a Delta Connection CRJ700. ExpressJet (formerly Atlantic Southeast Airlines), GoJet and SkyWest Airlines operate CRJ700s for Delta. Most of the Delta Connection CRJ700s operate out of Delta's hubs in Atlanta, Detroit. The Delta CRJ700 has 65 seats with 9 first class seats, 8 Economy Comfort seats (more legroom and more recline then regular economy) and 48 economy seats.
Below is a Delta CRJ700 seat map: