I agree that a sled would be a pain. But I had one with the Edge. Even though I never kept it on the device, I used it for the thin modem a time or two a day, a daily backup and finally an eyemodule when I found one for $10 at staples. I think a module sled would work with all communicators, but not with the 90, since it's OS4. (But then I'm guessing.)