Not sure what you are asking here. I've dealt with both of those seats. From your photos, it looks like the pin lengths are different. You just need to adjust the pin length so that the seat latches correctly. By correctly, I mean that if too loose, it will rattle up and down. Too tight, and it will be very hard to unlatch using the key. The loop is for attaching the lanyard that keeps the seat from flying away if not latched.