Great tool to mark the position of knots on rings for djembes and dunduns. Just place your ring on it and mark the crossing on the ring. Easy way to get a symetric order of knots on rings. There are different knot spacer with a different amount of crossing point aviable related to the kind of instrument like small or big djembe, calf or cow skin djembe, kensedeni, sagban or dundunba. The knot spacer is made of durable plastic and got a dimension of 70cm x 70cm in total.