SeeMeCNC Rostock MAX v2 Assembly Manual page 296

Length on Move specifies how much filament will be backed out of the hot end during a non-
printing move.
Length on Tool Change is specific to multi-extruder systems. If the slicer is changing to a new
extruder, it will retract the material out of the current hot end by this much. This works in conjunction
with wipe towers and wipe shields.
Speed dictates how fast the extruder drive will pull the filament out of the hot end. Higher
speeds can assist in preventing already-melted plastic from oozing or leaving strings on the part being
printed. It also controls how fast the filament will be returned to the hot end when the non-printing
move has completed.
Z-Lift is used to lift the nozzle off of the part as each retract finishes. This can help prevent
blobbing.
Minimum Travel Requiring Retraction is used to prevent retractions during very short moves
when retraction isn't really necessary. When executing a non-printing move, the nozzle will have to
travel at least this distance in order to trigger a retraction action.
Finally, Minimum Extrusion Requiring Retraction specifies how much filament must be
extruded before a retraction operation is permitted. This helps prevent instances where a retraction
operation would occur before the hot end had the opportunity to actually extrude material.
The Cooling page covers parameters relating to layer cooling.
Enable Extruder Lift if set, will cause the hot end to lift up
from the part to allow cooling.
The Fan Speed section controls how and when the cooling layer fan is used.
Minimum and Maximum Fan Speed controls
the lower and upper limits of how fast you want the fan
to go when it's enabled. If you specify a minimum
speed, the slicing engine will automatically vary the
speed of the fan between the min & max values,
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