The Kommit bicycle towing system is a unique towing system designed to make it easier to tow other cyclists whether on flat roads or uphill. It is made by Kommit Mobility, a German-based company that specializes in developing innovative transportation solutions for urban mobility.
The towing system consists of a heavy duty leash that retracts into its casing when not in use. The casing can be mounted under the bike's saddle that's doing the towing. The leash can be to the handlebar of the bike to be towed. It's great for towing kids or other people who don't have enough strength to paddle uphill. It can also be used to tow runners in case they need a little pull.
The Kommit leash has a maximum tensile load of 265lbs (120kg) and the whole system is only 4.9oz (139 g). If there's no way to attach the leash to the bike to be towed, Kommit also has a Chip Mount that mounts on the handlebar for hooking the leash.