Ryobi Expand-It 18-Volt Lithium-Ion Cordless String Trimmer Power Head ( Attachment Capable, Attachments, Battery and Charger NOT Included) - Walmart.com
Ryobi Expand-It 17-1/2 in. Universal Hedge Trimmer Attachment part no. RY15704 - YouTube
RYOBI Expand-It 18 in. Straight Shaft Trimmer Attachment RYSST44 - The Home Depot