These aluminium sling rings are purpose made for baby wearing and are in stock and shipped to you from within Australia.
These sling rings are good for most fabric weights including two layers of light materials. They have an inner diameter of 7.5cm and an outer diameter of 9 cm. Colours - silver, black.
$11.00 per pair.
How to sew a variety of slings yourself:
Jan Andrea's Baby Related Crafts
And did you know you can make no sew slings using a pair of sling rings? Here are some links that you may find helpful.
Sling rings can be used to simplify a number of wraps, especially
back carries. See Dallas's
roundup for Tibetan, shepherd's carry, double hammock,
rucksack carry and back wrap cross carry - with pictures and videos
of how to do it yourself.