Your aluminum track is the runner that fits at the top of your window. They operate the slats accordingly. You have two options when choosing your track colour, white or brown. This option is in case you have white or brown windows and therefore you can co-ordinate with them.
The dimensions of this headrail is 30mm wide x 27mm deep.
The vertical blinds come in two slat width which is 89mm and 127mm. When choosing a slat width have a look at your windows and decide whether your windowsills will fit a 89mm or 127mm slat. Remember that the blinds will need to come out a little bit more than the slat width especially if your windows have handles that stick out.
It is your decision to have the controls on the left or right. TIP: look out for opening windows when deciding where to put your controls, when the window is open the controls may swing. You have two controls, a chain to rotate the slats so they are open or closed and a cord to pull the slats to and fro.
By pulling on the cord control on your track this will draw your slats back in to the position you choose. They can either draw all to the left or all to the right or they can split in the middle. Should you choose them to be split in the middle it will have the effect like a curtain drawing back.