Keep your SKIL 40V 20-inch lawn mower cutting at its best with a replacement 20 In. Lawn Mower Blade. The 20-inch replacement lawn mower blade is compatible with all SKIL 40V 20-inch cordless lawn mowers (PM4910, SM4910, SM4910C, SM2010C, and PM2010C) while universal compatibility allows it to be installed on most other lawn mower brands. The dual-purpose replacement blade can be used on your lawn mower for bagging or mulching. It’s easy to install so you can get back to mowing quickly.