Advanced Track 100mm Ceiling Suspension Chrome or Black

Which support do I need to fix the track to a sloping ceiling?
For installation on a sloping ceiling Product Ref: 1343 is required.

Does the 100mm measure from ceiling to top or bottom of the track? Thanks P
Using this suspension will give you a gap of 100mm from the ceiling to the bottom of your track.

How many ceiling suspension units do you need for a 2m track? Are they sold individually?
For the smaller spotlights 3 supports is enough on a 2.0 metre track. When using heavier spotlights 4 supports will stop deflection in the track. The supports are sold individually.