Circular slide rule with pouch, radiation dosage calculator, Radiac No.1, paper / fabric, made by B R L (Blundell Rules Limited), Weymouth, England, 1951-1956
Calculator, Radiac No.1
Circular sliderule device for calculating radiation exposure: as Dose Rate
Mfr: BRL (Blundell Rules Limited), Weymouth, England
Ref No. 665-99-9121-0060
In waterproofed cloth pouch. Instructions are on the reverse.