Bicyclebungee Tandem Cycling on Two Bikes, Smooth Bike Tow, Ride With Your Kids! Tandem bicycle riding with two independent bicycles--Ride together, not alone! Made of carbon fiber: light, durable, safe, and easy-to-use. Very easy to install and remove High strength bungee cord absorbs all of the tension for a smooth bike tow and built-in automatic cord reel retracts cord smoothly and safely Fits all standard seat post diameters from 27.2 mm to 31 mm The only bike towing accessory of its kind-developed in New Zealand, the land of bungee!