Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Heavy duty and long lasting!

I bought these along with theGrass Gator 8010 Load n' Cut Replacement String Trimmer Head. What an excellend combo! I have a nice 4 Cycle Troy Bilt trimmer but was so frustrated with the bump head on it and the string would not last through a single pass around the yard.With these inserts and the Grass Gator I can edge the yard several times on a single string before replacing them. Highly recommended!