Parker SoloEdge

Precut blades appear to be narrower at the point that gets snapped on a DE blade or at least my Leaf pre cut SE blades are narrower, and so fit better. Don't know about other pre cut blades. A snapped DE blade extends over the ridge of the razor head at that point so I think that cutting a DE blade is better than snapping at least for the Parker Solo Edge. Just ordinary scissors needed. But it's a small point - just be careful and don't cut your fingers.