Sledding Harness

What material could be used to make a torso harness to pull a sled and where can I buy?
Basically I need belts strong and something to connect the belts together.
If you already have the look of the sled in the manufacturer of spare parts. However, if you have a house built sleigh (one made by your school / AG department store, for example) can mount a harness with a car / truck tire tube and some tie straps. The tube could easily slip into the head and arm and allow the person pulling the sled some elasticity by the initial pull to pull. Kind of buffer as a shock. Consult a local tire shop for the tube, roughly around $ 15-20. Need not even be able to keep the air, go down that road to see if you can get to donate one for you. The tie-downs are less than $ 20 at any big box store.
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