vertical and big rounds. sounds good right no lifting, until you try to move that chunk sitting on the flat side under the wedge. even if you dig the toe plate in a bit 50+ # chunks don't like to move and you are on your knees or bending over trying to get purchase power. I am about 160# I just do not have the mass to move something 30" or better in dia. by around 16-18' tall ( and better believe tha round of oak that size is in 75-100# area) in the dirt almost not possible on hard surface as well. That's what I found some 20 years ago. same splitter now but rebuilt heavy duty ( 30ton I bent the foot plate and sprung the beam over the course of time hence the rebuild) horz only now. those big rounds get noodled( sawed) down to where i can moving them with out ripping myself up, it was only 30k for the hernia op, just as soon not do that again. Used to bust them up with sledge and wedge, at 71 parts of me ain't what they used to be. wood in pic starts at 20"dia