Two baby carriers

I have two baby carriers. $5 each, or $8 for both. Both bought new, still in clean and great condition.

1. Infantino Flip 4-in-1 Convertible Carrier
   https://www.amazon.com/Infantino-Flip-4-in-1-Convertible-Carrier/dp/B00M0DWQYI
   Works great with small infant, no infant insert needed.
   Easier to use (allso lighter and more compact) compared to ergobaby. The band on parent's lower back is probably too narrow and after my kid turned 6+mon I feel lower back discomfort if use it for > 30 min. My husband thinks it's fine on him. For heavier kids I'd use the following:

2. Ergonomic Baby Backpacks with Hip Seat
   https://www.amazon.com/Carriers-Ergonomic-Backpacks-Toddlers-Adjustable/dp/B0725GFGMG
   Backpack can be detached and use as a hip seat only. Or attach backpack and use as a carrier. Works only if baby can sit (at least supported sitting). I think it is more spacious for baby compared to ergobaby. Comes with a storage bag.