I'm really confused about the meaning of direct fit on a derailleur. I currently have what looks like a a Shimano Tourney RD-TY 500 on my cycle. This derailleur hangs from a hanger on the cycle which looks like this (link below.) The bit I don't get is that all these direct fit derailleurs look exactly like the one I have, but will a direct fit onto a derailleur hanger like mine? I've also included a link to the derailleur on eBay that looks the same as mine, but state they are direct fit. Thank you! https://www.ebay.co.uk/itm/Compatible-Carrera-Mech-Hanger-with-bolt-carrera-valour/273234741328?ssPageName=STRK:MEBIDXT&_trksid=p2057872.m2749.l2649 https://www.ebay.co.uk/itm/New-Shim...874281&hash=item3f6f5a9d42:g:ttIAAOSwB09YK6Ht Here is the derailleur on my Cycle you can see it's attached to a hanger. So will the eBay one I have linked to on here fit or not? Cheers..