Hello! Let me know if you have any questions about the item. 
Hi there. How many tires can this kit convert?
2!
How durable is the conversion after its done?
Like a new tire
I am in New Jersey, do you know the shipping costs or will you ship it to me free of cost?
shipping is included in the price
Sounds great. I actually would like to purchase two sets. Would you take $40 per set?