Thanks... Asked this Particular Question coz DEMU's coming with various Window designs.
1) Earlier DEMU's had Window Grills similar to ICF Coaches, liitle outside from Window, bent at the corners & leanable (RF Friendly).
2) Then few came with 2 Strong Rods, which are inside the windows & you couldn't lean out. Mostly in Grey & Violet bottom livery.
3) Then few came with...
more... Thin Grills which are Slide-able open, Ex : Kadapa DEMU, & few running between Pune - Daund. RF Friendly but not Safe. CR replaced one Overnight Unreserved Passenger running between Solapur - Pune with such DEMU & people were/are complaining about its Safety, as it can lead to easy thefts from Windows during Night.
4) Then this new design used in Bidar - Gulbarga DEMU, Permanent Grills.