Metal precision linen testerEschenbach's precision linen testers are designed to meet the requirements of technical applications, they feature: Biconvex lens made of high quality silicate. Brass frame, chrome plated, silk matt finish Variants: Size Magnification Cut out Height 1254 11 mm 48 dpt 12 X 10 x 10 mm 23 mm 1255 12 mm 40 dpt 10 X 15 x 15 mm 27 mm 1256 15 mm 32 dpt 8 X 20 x 20 mm 33 mm 1258 20 mm 24 dpt 6 X 25 x 25 mm 42 mm 1259 28 mm 20 dpt 5 X 30 x 30 mm 53 mm