 The Sovereign came in satin chrome and gold @-@ plated models , with leather pouches and fitted wooden cases . It had an 8 @-@ digit seven @-@ segment display that used red light @-@ emitting diodes , with a <unk> point to the right of each digit that could be illuminated as necessary . Power was provided by two 1 @.@ 35 mercury button cells . The Sovereign measured 36 by 141 by 12 millimetres ( 1 @.@ 42 in × 5 @.@ 55 in × 0 @.@ 47 in ) , which made it small and <unk> compared to other calculators of the time . 
