Was wondering if someone could help me figure out the difference between these two 4 packs of lock nuts and why one is cheaper than the other(don't expect to get an answer but just throwin it out there)

4 pack of hex 17 lock nuts(has the different specs...weird as well that it says both sizes work on all cars LOL) $61.54

http://www.nengun.com/rays/17-hex-lock-nut-set

Same thing here but no size options(also it is the first set of nuts, above the duralumin and GT-C set) $51.54-$61.54----No real descriptions of why the price differences

http://www.nengun.com/rays/duralumin-nuts

Thanks guys, still waiting for a response from the website so in the mean time....