Safety The cordless weed wacker has added a safety lock button to prevent accidental start-up. You need to press both the safety button and the switch simultaneously to start the cordless weed trimmer. Cordless Not limited by power cord, you can use it anywhere. 3 Types of Cutting Blades It can be use as weed wacker or edger trimmer for weed, grass and bush. Plastic blades are suitable for soft grass. Stainless Steel blades are well for older Adjustable Height The weed wacker battery powered has a one-key adjustable telescopic pole can adjust the length from 35-47 .2inches.