A vast majority of the spring chain tensioners we sell are designed to fit onto a derailleur hanger, with the exception of the Echo SL and TR which fit between your hub and frame.
Sprung chain tensioners are our most popular sellers on 26" bikes for good reason, they offer consistent and reliable tension and once they are set up rarely need any adjustment. As with most products, if you can afford to spend a little extra it's worth it - as you climb up our product range the quality improves and our double wheeled tensioners help to eliminate any skipping issues that can come about when using small sprockets and single wheeled tensioners.
When setting the tension, do not bend the spring with excessive force - this will damage the spring and reduce the amount of tension it can provide.
The Echo SL tensioner is designed only to fit Echo SL or TR rear hubs, it will not fit any other model of hub. To fit, you remove the drive side axle spacer and replace it with the tensioner.
Most of the double-wheeled tensioners are designed for use with 3/32" chains, but often can be modified for use with 1/8" chains simply by adding a washer either side of the jockey wheels. If you need any tips just ask!
TartyBikes Ltd, Units 3-4, Club Street, Bamber Bridge, Preston, PR5 6FN