I currently bought the lens cap (58mm) for 2.99 and do not regret a penny. The shipping was very quick with my standard shipping. The product has an internal clamping and can be better attachment and detachment, as the standard Canon lens cover therefore. Furthermore, here has this article an eye, so you could thread a small cord. In any case, this cover will match the following objectives:
Canon 18-55mm 1: 3.5-5.6 IS Canon 55-250mm 1: 3.5-5.6 IS Canon 75-300mm 1: 4-5.6
Especially because flaps every now lost quickly, I bought at this low price direct two, to always have a spare in my camera bag, if I go times should lose a Canon original cover.