In reply to muppetfilter:
I remember easy-rider etriers (I think that's what they were called) - single adjustable foot loop.
Paul Parker (of Leicester's Bowline) used to solo things like Mecca and The Prow with them after the sunday lunchtime pub visit. Mind you there were lots of things that Paul (still with us I believe) used to do which us newbies found a bit unnerving - he wasn't what you'd describe as risk averse 😁
Post edited at 19:58