Specification:Function: adjust the strap lengthMaterial: alloy steelKit Quantity: Metal Watch Band Adjuster +3 Spare Needlecolor: redNet weight: 24gGross weight: 27gSize: 6.5 x 1.5 x 1.5cm/2.56" x 0.59" x 0.59" (maximum adjustable width 3.2cm/1.26") Instructions:1. Open the strip and place it on the movable slot of the watch band adjuster.2. Gently push the slot into reasonable place.3. The thimble of twist grip aligned with the pins of the strip.4. Rotate the handle directly by hand.