I have a couple of red bands. More for the novelty of it though than needing the low gear. I've just come accross these and never have bought one. It's obviously a great way to gain a gear with out cables and shifters. They work good. The only complaint I have is they are both a little noisy in the low gear. Don't know if this is normal or they need greased/rebuilt.
What color band? Red, Blue or Yellow? Both the Red and Yellow have a low first gear and a 1:1 second gear. The Blue-band is a 1:1 first gear, overdrive second.
They are not bad to work on...but there is a special tool needed (it can be made!)
They were on different Schwinn models (some early Sting Rays & middleweights)...