4000/2-30 Dremel 2 Attachments, 30 Accessories High Performance Rotary Tool features a high performance motor providing maximum power and performance at all speeds with a variable of 5,000RPM to 35,000RPM and electronic feedback circuitry for consistent performance even in demanding applications. 4000/2-30 Dremel 2 Attachments, 30 Accessories High Performance Rotary Tool features an innovated airflow system where ventilation mechanism helps prevention of heat build-up for smoother, cooler and quieter operation and has a slim/ergonomic 360° grip zone for added comfort/grip.