For ETRSi & 3 lenses/2backs/2finders, I use a LowePro Slingshot 200. For Mamiya 7 and/or Rolleicord Vb plus acc, a LowePro Slingshot 100 to the site and then Op Tech Pro for the Bronica and a custom made (no stretch) strap for the Vb. For Zenobia 645 a Rapid type sling.