SpecificationMain Color - BlackMain Material - SteelDetailsProduct Features - Adjustable dumbbell,8 pcs black plate,with a handle barPatent of company,you can buy with confidence with it.Rubber coated dumbbell,with a black plastics base,Two-ways regulation,more convenient for customers to use Description - Two-ways regulation rubber coated dumbbell ADJUSTMENT RANGE - 3LBS,16LBS,28LBS,40LBS,42LBSSTRENGTHENING Two-ways regulation rebber coated dumbbell BE SURE TO SYNCHRONIZE YOUR BREATHING CORRECTLY - BREATHE OUT WHEN TAKING THE STRAIN AND BREATHE IN WHEN RELEASING PRESSURE.IMPROVING STAMINA - CONSIDER PERFORMING AN EXERCISE UP TO 15 TIMES(REPETITIONS) SET AND THEN 3 TO 5 SETS I.E. 10 REPETITIONS 3 SETS WITH A REST BETWEEN EACH SET.IMPROVING MUSCLE MASS - CONSIDER PERFORMING AN EXERCISE AT LEAST 6 TIMES(REPETITIONS) SET AND THEN 3 TO 5 SETS I.E.TAKE A SHORT BREAK OF 1 TO 4 MINUTES BETWEEN EACH SET OF EXERCISES.3-5 TRAINING SESSIONS A WEEK,WITH A DURATION OF 20-40 MINUTES,IS RECOMMENDED.