Test Tube Stand - 'Z' Shape, made of Aluminium Sheet-EIS-CH0713A offers a thoughtfully designed, durable resource for hands-on learning. ‘Z’ shape, made from 18 gauge aluminium sheet, anodized and 3 tier. ‘Z’ shape, made from 18 gauge aluminium sheet, anodized and 3 tier. With 5 holes of 23 mm dia., 6 holes of 20 mm dia. and 8 holes of 13 mm dia. Overall height of 75 mm and length of 200 mm.