Where: For Izloo the member above knows where to get it, cost it pretty high.
For my corolla he jacked the car all 4 wheels emptied from the regular air and then he filled it with nitrogen air there was separate line/pump for it in his shop.
Got it in my RX115 too for bike he discounted to Rupees 50/- for both. after reminding him that you charged me 200 and that was quite high
RX 115 by Kamran Aslam, on Flickr