ECHO SRM 225i Line Trimmer Straight Shaft 21.2cc I-75 Start EngineECHO SRM 225i Line Trimmer Straight Shaft 21. 2cc I 75 Start Engine A Speed Feed head and i 75 starting technology Features: 21. 2 cc professional grade, 2 stroke engine for outstanding performance i 75 starting system for reduced effort starting 59" straight shaft Engine vibration reduction system for operator comfort Speed Feed trimmer head re loads in seconds without disassembly