KLP® Hybrid Polymer Bridge Sleeper Installations KLP® Hybrid Polymer Sleepers: High-quality ductile polymer, reinforced with steel. Strong, stable, sustainable, recyclable. Images Height Adjustable Transoms Installations Belgium 2018Malaysia 2017 (girder bridge)Netherlands 2010, 2011, 2013, 2014 (canted bridge), 2017 (ballasted bridge)