This will make a great insulated unit for queen rearing.

http://www.paynesbeefarm.co.uk/nuc-m...-for-poly-nuc/

Last year I was using 3 ekes to put 6 frames above a Paynes nuc.

These are very handy for making up a queenless cell starter.
I drop in a frame of grafts and then move the frame to a queenright colony above an excluder for finishing 24 hours later.