The casements will need to have the beading on the INSIDE (to prevent continued access being gained by means of removal of existing external beading - illegal access has been a recurring problem to me for sometime!). New casements to be installed into three existing window frames in place of the present casements. The approximate size of all casements - 4ft x 23inches (metric equivalent to apply). Ideally, would be necessary to view existing windows in situ to obtain exact sizes, and would be very grateful if you could oblige in this respect.