6B/1503 - Holder, Deviation Card Mk. II 6B/1503 - Holder, Deviation Card Mk. II
This item is made of clear Perspex and all our stock of these has bowed slightly over time, unless they are designed to be like this; we do not know!

The holder takes a deviation card Form 316, but we have not found a stock of these at present.
We can supply an excellent re-print on the right coloured card at £1.50 each.