Whether you need 1/2"-20 nuts for your trailer or not, this is a good choice. Normally McGard is sold in packs of 4 so you can buy 4 packs of regular nuts and a pack of locks, if you don't need or don't need locks there is no reason not to buy two of these 10 packs, in fact it's cheaper to buy them in this form as 5-4 packs. As for the nuts themselves, I haven't found any chrome nuts that even come close to McGard. While rust can appear on them, a quick buff will remove it and it seems to flake