igma ; ▁it ▁can ▁be ▁quickly ▁ex changed ▁for ▁the ▁second ▁reflect or ▁wheel ▁with ▁prepared ▁reflect or ▁plug ging . ▁Whe els ▁I , ▁I ▁and ▁III , ▁whose ▁w iring ▁now ▁correspond ▁exactly ▁to ▁those ▁of ▁the ▁En igma , ▁have ▁adjust able ▁rings ; ▁they ▁can ▁be ▁moved ▁around ▁the ▁body ▁of ▁the ▁whe els ▁and ▁have ▁a ▁fixed ▁pin , ▁which , ▁by ▁anal ogy ▁with ▁the ▁En igma , ▁is ▁to ▁be ▁called ▁the ▁turn - over ▁not ch , ▁although ▁mechan ically ▁it ▁is ▁not ▁so ▁made . ▁O pp os ite ▁the ▁whe els ▁I ▁and ▁II ▁are ▁two ▁sens ing ▁points ▁which ▁pick ▁up ▁the ▁turn - over ▁not ch ▁as ▁it ▁passes . ▁U ▁is ▁pl ugg able ▁as ▁in ▁a ). ▁In ▁addition ▁there ▁is ▁between ▁the ▁point ▁of ▁input ▁and ▁I , ▁a ▁ste cker ▁S ▁like ▁the ▁En igma ▁ste cker . ▁The ▁following ▁two ▁methods ▁of ▁working ▁are ▁possible : ▁Working ▁on ▁own ▁w iring : ▁N 1 ▁N 2 ▁and ▁N 3 ▁are ▁given ▁a ▁certain ▁pin ▁arrang ements , ▁there ▁being , ▁it ▁is ▁true , ▁certain ▁limitations ▁to ▁the ▁number ▁of ▁act iving ▁p ins . ▁W heel ▁I ▁moves ▁as ▁under ▁a ) ▁above . ▁For ▁wheel ▁II ▁there ▁are ▁the ▁following ▁ 3 ▁causes ▁of ▁movement : ▁ ▁An ▁active ▁pin ▁at ▁the ▁sens ing ▁point ▁of ▁N 2 ▁causes ▁II ▁to ▁move ▁on ▁one ▁place ▁as ▁in ▁a ) ▁above ▁ ▁When ▁the ▁turn