The Werner Long Body aluminum ladder jacks for stages up to 20-inch width enable the use of planks or stages between Type 1 or 1A ladders. Put the jacks a foot away from each end of the plank or stage them up to 20 inches wide, then use the clamps to hold the plank or stage together. This is a short body ladder jack. Ladder jacks allow you to run planks or stages between a pair of extension or single ladders. Ladder jacks should be placed one foot from each end of the plank or stage. They should be used on type I or IA ladders. Sort body jacks will support stages up to 14 inches in width, long body up to 20 inches. Werner ladder jacks use a platform clamp system to clamp the plank to the ladder jacks and help tie the entire system together.