The is fitted with a 'one touch'hit adjuster. Settings are altered by rotating the metal adjuster knob at the top of the unit. the full range of settings can be achieved with less than one rotation.when the metal tab is covering the number one,the machine is set to its hardest hit.when number 10 is covered,the machine is set to its lightest hit.Bits 1-10 change from hard to softThe needle retainer can be tightened and lossened using the adjuster knob.screw the knob gently in a clockwise direction until the pulley is in contact with the needle and keeps it in place on the rubber nipple.do not over tightened as this will put unwanted strain on the motor.If the adjustment knob is loosened during operation, the O-ring needs to be replaced, After replacing the new O-ring, a small amount of lube can be applied to make reassembly easier.Package Include:1 x Tattoo Rotary Machine