As of public testing v0.0.11p17, the F/A-26B has conformal fuel tanks as an option. They are found next to the TGP using the hangar configuration menu.
CFTs cannot be jettisoned, and they count as part of the internal fuel tank meter. It should be noted that CFT's make a substantial negative impact on your TWR, more so than the external fuel tanks. The external fuel tanks hold 2200 or 4200 liters of fuel. The CFT's hold 6400 liters. While great for long range missions and freeing space for more payload, this makes combat maneuvering much more difficult with these on and full. These are not recommended for air-to-air missions.
Weight: 443kg (this number does not seem to factor in the fuel load like the other tanks do, so don't go by this. Look at TWR instead.)