You can Google Hovabator or GQF for more information on what they sell. The 1602 has two small windows, which i thought would be better than the one big window that the 1588 has, but the 1588 has two layers. I put a baby blanket over the 1602, and it keeps much better temps.
The 1602 that I have is a still air, but I wired a tiny computer fan to a power pack to turn it into a forced air incubator. If it sweetens the deal, i can include the fan.