17 new interlocking panels, 18" deep x 24"wide (partial box). Protect sidewalks, driveways, & patios from root damage - redirects roots away. the ones I've used have worked great, stopped a large tree from growing its roots under our paver sidewalk.
Here's an Amazon link with more info... https://www.amazon.com/dp/B00BJWCIV2?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_2&th=1