Toro53743 570 Pop-Up with X-Flow Sprinkler, 6-Inch

Do these have a side inlet, or jus that the bottom?

Will the new pop-up fit inside an old 570 housing already buried in the ground.

Do the 6inch x flow models say "lf" at the top?

Does this require purchase of additional Mist heads or is the red top it comes with meant to remain in place