in the product description it is indicated that the depth expands to 29".  I thought it would simply stretch and stay in place, nothing indicated it would need to be held in place by the screw type pins included.  I would never had ordered them if I knew about the pins, the couch is brand new, and I would never use the pins due to fear of damaging the couch material and voiding the warranty.  They do stretch to the depth of the arm, but then recede.