1. Normally it come whole set. But if want to get separately also can but make sure the installer is knowledgeable with what he or she is doing.
Now days any TOM, DICK and HARRY is doing it which some will give customer headache. For us is OK because we get to settle their problem but of cause customer hv to pay for the service. A lot prefer cheap and end up hving headache but still want to settle the solution at cheap price. For us if want cheap then hv to go and study how to trouble shoot the problem ourself then it will be cheap.

2. Trackless dun hv stopper but holder to align when the gate close and prevent ppl from lifting up the gate. If trackless without holder but with stopper then ppl can just push or pull the gate apart unless it hv an autolock at the center of the gate. If without stopper or holder so far dun hv.