These aint the lightest but they cheapest. Under 15 dollars you can buy everything at the airplanedepot/homedepot.
http://www.cessna150152.com/forum/ubbthreads.php?ubb=download&Number=30054&filename=Tie Down Set.jpg

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Rob
N66707 75 C150M "Number 2"
Tacoma WA. KTIW