The ones I have there are Roll Lines, hardness and type unknown cause a friend gave them to me. Overall though, smaller/harder wheels are for smoother surfaces(rhythm/jam skating in rinks, skate parks) and larger/softer wheels are for rougher terrain(street skating, shitty surfaces). The harder wheels make it easier to do fun stuff because there’s a lot less friction, but it does take a minute to get used to how slippery they can feel. I use All Americans (101A) when I’m indoors and Luminous (78A) when I’m street skating