Tutorial from Wraplena:
Fabulously Wrapped tells us more:
Double Hammock is a base size carry that is a favorite of many. It is leaner proof and medium leg straightener proof. It is a very supportive carry that is very comfortable when the chest pass is done correctly. It is a naturally low carry due to the chest pass, so it is more suitable for older babies, although squishes can also be worn in a higher DH because their weight usually won’t create a comfort problem even when the chest pass doesn’t support much of the weight.