Inch and Millimeter Dimensions: The T square ruler is available in metric and foot scales, with depth measurement units marked on the side 1/4, 1/2, 3/4 to meet a variety of measurement requirements. Can be used to measure the length and width of objects, as well as depth and height. Ideal for engineers, designers and architects to mark and scribe. Slide Ruler with Stop: There is a fine notch at the end of the ruler. Set your stop, insert a pencil into the notch and you already have a marking gauge. The powerful stop is attached with two thumbscrews and thus remains fixed to the ruler. Simply slide it off the ruler and through the slot in the ruler sheet to stop and fix it in any position and effectively prevent slipping. Easy to use: The metal ruler has an adjustable positioning lock. The ruler stop can be moved to the desired position according to the measurement needs. The sliding mechanism locks well and allows easy measurement on the surface. The two thumbscrews hold the slider securely and do not tend to loosen during use. Versatility: The engineer indicator ruler is a practical tool for schools, offices, home schools, architects and engineers. The precision pocket ruler is a versatile and perfect metal ruler that is suitable for architects, draftsmen, engineers and artists. You can measure data accurately and conveniently anytime, anywhere.