Color: blue+white Material: high quality plastic Application:measuring orings inner diameter,outer diameter,thickness,for AS-568 / BS1806 standard Telescoping O-ring Measuring Gauge With this handy gadget, it s easy to determine the size of almost any AS-568 / BS1806 Standardand Size O-ring. Section size is identified by using the slots at the top. The AS size number of small O-rings can be found by matching them with the silhouettes along the sides of the gauge. Larger O-rings are placed around the two halves of the appropriate spindles at the top of gauge. The slide is then extended until it is taut, and the AS size number is shown in one of the small windows near the top of the main body. Accurately determine o-ring sizes in all AS568 standard cross-sections up to 13 ID. The telescoping slide is easy to use, just place your o-ring around the holder on one side and around the notch on the other size. Slide out the gaugeuntilthe o-ring is taught but not stretched. The standard AS568 size will display in the box. This is a brand new item that comes in a retail stylecardboardcontainer. O-ring sizes: 001-050, 102-178, 201-279, 309-382, 425-455