Medicap 25-Pack FE Systemic Iron Tree Implants for Control of Iron Chlorosis, 3/8-Inch Fast green-up for iron deficient trees One treatment lasts 2 to 3 years 10 implants will treat a 14 inch diameter trunk Tools required to treat: tape measure, cordless drill with 3/8 inch bit, hammer and bolt or dowel rod Ready to install - no measuring of chemicals