On Monday, January 15, 2018 at 8:36:40 AM UTC-8, Roy B. wrote:
Does anybody know a source for the inflatable lumbar bladder (with hose & pump bulb) that goes in some parachute packs - like the old Security 150s?
ROY

The ones Security used were sourced from a medical supply house. They are used to make wheel chairs more comfortable. You might check with a local supplier of such gear.