Quick change lawn mower blades

A blade for a lawn maintenance device comprising:

• opposed end edges and opposed side edges, the blade adapted for mounting onto a lawn maintenance device for rotation about a center axis extended transverse to the blade, the blade having a blade major axis;
• the blade defines a central aperture located on the center axis;
• the blade defines a pin aperture positioned a distance from the center axis and a distance from the blade major axis;
• and
• the blade defines a force finger aperture positioned a distance from the center axis and a distance away from the pin aperture,
• wherein the pin aperture is located on a pin line that is not parallel to the blade major axis and the pin line passes through the center axis,
• wherein the force finger aperture is located on a finger line that is not parallel to the blade major axis and the finger line passes through the center axis and is radially offset from the pin line,
• wherein the central aperture is centrally located and is asymmetric about the center axis,
• the central aperture comprising
• a first portion having a long dimension, a short dimension and a first centerline along its long dimension;
• and
• a second portion partially intersecting the first portion, the second portion having a long dimension, a short dimension and a second centerline along its long dimension, wherein the first and second centerlines are offset from one another along a direction substantially perpendicular to the direction of the first centerline and the second centerline.