This Listing is for MEDIUM RESISTANCE CORDS. SPEEDSTER POWER RUNNER Strength and speed trainer. The Power Runner develops high knee action and promotes balance. As the player runs away from the anchor point the Lightning Cord tightens forcing the player to exert more strength to keep the cord stretched. Perform explosive running drills without compromising technique. GUIDELINE FOR CHOOSING PROPER RESISTANCE LEVELS: MEDIUM resistance for Beginner and Intermediate athletes under 110 lbs. (HEAVY for Advanced athletes under 110 lbs.) - HEAVY resistance for Beginner and Intermediate athletes over 110 lbs. (ULTRA HEAVY resistance for advanced athletes over 150 lbs.) Take into account the athlete's age versus weight when ordering. Our Ultra Heavy is approx. 50% more resistance than our Heavy and comparable products from other sources which are typically only offered up to Heavy. POWER RUNNER TRAINING PACKAGE INCLUDES: 2 - Padded Adjustable Ankle Cuffs with Quick Release Snaps, 2 - 4' Lightning Cords with Nylon Safety Sleeved Technology, stretch up to 12', 1 - Anchor Strap. Made with the highest quality premium rubber completely covered with a durable and protective nylon sleeve to stand up to the rigorous demands of professional and residential use. The NEW Generation of Resistance Cords! WORLDWIDE FITNESS PRODUCTS: The principal of this company has been manufacturing, selling and distributing fitness and sports training products for over 20 years. COMPANY MISSION STATEMENT: To offer high quality products and services at a fair price!