New 2, 3 and 4 Row Tip and Roll Preferred Bleachers with Double Foot Planks. Preferred bleachers are the same as our standard aluminium bleachers but with the addition of double foot planks on all rows. Aluminium seat planks and frames. Preferred bleacher are the same as our standard aluminium bleacher but with the addition of double foot planks on all rows. Seat planks are 25.4cm wide non-skid aluminium. Four row bleachers do not exceed 76.2cm in height, therefor guard rail may not be needed!. 21' Long, 2 Row, seats 30.