30cm High Riser for Rectangle Stage Platform. Unique accordion-style folding stage platform riser provides sturdy support for your platforms. Deceptively lightweight and compact, risers lock securely to platforms via our unique platform locking screws. Riser height can also be increased up to 160cm high using the optional ISREK riser coupler (for safety, never couple more than two risers). Risers are available for square, quarter round, triangle and step platforms in heights of 20, 30, 40 and 60cm.