9-Level Adjustable ResistanceThis arm trainer has 9 levels (20-270lbs): 1-3 (20-60lbs) for womens arm circles, flabby arms tightening, warm-ups/beginnersideal for women. 4-6 (60-160lbs) for tricep dips, shoulder shaping, intermediate training, suiting mens initial muscle building. 7-9 (160-270lbs) for pros chest squeezes, bicep bulking. Adjustable with included wrenchno extra tools, 3-5 mins to switch (manual-guided). Heavy-Duty Build:High-strength metal springs with full leather coating (prevents rust & pinches,test-proven to last 3x longer than plastic covers) ensure this arm trainer endures daily use. Thick non-slip foam grips stay comfortable even during 30-minute workouts, enhancing the arm trainers usability. Safe for home use with kidsno exposed springs to cause accidents. For All UsersLevel 9 (270lbs) suits men, enhancing chest/arm definition with 15-minute daily squeezesconsistent use fosters sculpted lines, a practical trainer. Women: Level 1-3 tone