Review on 64In Heavy Duty Marine Grade Bungee Cords With 2 Hooks - SGT KNOTS (4Pack) - Perfect For Bikes, Tie Downs, Camping & Cars! by Marcus Munoz

I only just got the bungee cords so I cannot judge the durability and sturdiness. They do seem to be durable but I won't know for at least a year. What I am disappointed about is that the bungee cords have a weak retraction. I am using the cords as shock cords on the tie downs for a 20' x 20' tarp. There are 12 tethers holding the tarp. As they were they would be stretched out in just a moderate wind. I had to double up each bungee by putting both hooks in the same grommet and then tied the rope on the other end on the bungee. I attached ground lines with 3' to 4' long ropes. That barely provided enough retraction power to keep the tarp properly tensioned. However, the rigging has barely been tested because it has been up for only about a month and no big storms have come along.