This lift kit raises Roll-a-Cot® 3".  However, there is an installation process that you will need to perform each time the lift kit is installed.  Please see instructions below:

Installation instructions:   1)  Use a hair-dryer to heat the old leg tips for their easy  removal.  2)  Use a round file to remove all burrs at the very bottom of the cot-leg so that the riser slides into the cot-leg easily.  3)  Use a hair-dryer to heat the plastic-coupler on the riser so there is complete engagement between the cot-leg and the plastic-coupler.  4)  Wrap duct tape around the connection between the cot-leg and the plastic-coupler if more retention is needed.