Reliability: Placing the bow components in the correct position helps maintain the reliability of the bow components. Quality Materials: T Square Ruler is made of aluminum alloy,Nocking buckle pliers are made of stainless steel. String nocking points are made of brass. More : of the square T-ruler adopts Epoxy paint technology, rejecting scratches, and has two measurement units of mm and in.Nocking buckle pliers adopt Spring Design and Smooth Jaw Opening,Easy to use. 8pcs nocking points just righ, and the inner layer is made of anti slip nylon, which serves to fix and protect the bowstring. Widely Used: The kit can measure the height of the bracket, lock the position of nocking points, and that it meets the most commonly used configuration for debugging bows and arrows. Specifications: Material:Metal Size: 12.9x3.46Inch and 2.63x1.1Inch / 2.67x1.4Inch colour: Black Package Contents: 1 x T-shaped bow square 1 x nocking buckle pliers 8 x bowstring nocks set Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.