I haven't worn my sling yet because I don't know how to assemble it into 2 "rails" like they're talking about here in the directions :
http://www.comfyjoey.com/cj_rs_instructions_v1.pdf

I'm looking at pf 4 for the newborn directions...Any tips or advice? I just don't understand what they mean about 2 rails... Or how to get them...