... 35, 75 x 25, 75 x 35, 75 x 45 and 100 x 45mm 5. Track size options: 50 x 40 ... , 50 x 35, 75 x 30, 75 x 40 and 100 x 40mm 6. Length options: 2.95, 3.0 ... , 5.95 and 6.0m 7. Thickness options: 0.35, 0.4, 0 ... and 0.8mm Features of light steel keel: high performance, easy cut apart, non-deforming, simply installation, dry construction, light weight and environment ...