Faja. Its a cool wrap thing from south america.

This wrap can help with lots of things. Including;

• support during pregnancy and postnatal
• help where there has been a diastasis of the abdominal region 
• help with stabilising the lower back
• support the Sacroiliac joint (SIJ) 

They aren't hard to make and use. All you need is a sewing machine, some 100% cotton fabric (calico, duck or canvas)
The wrap needs to be about 2.5 mtrs in length and about 13 -15 cms wide.
Then you just need to tie it around the hips properly

Check out the handout HERE