It's my first helmet and I don't know which size to buy

Hello, I would like to ask for your help; The thing is like this: the circumference of my head is 59 cm, which is the upper limit of size M and the lower limit of size L, and I don't know which one I should buy. I can't try it on, since I'm going to make the purchase online. The helmet is the Leatt Allmtn 1.0 v21.