Adapterringisusedbetweencamera(orprojector)andlenses,itcouldmountkindsofconversionlenses,suchastelephotlens,wideanglelens,fisheyelens,andsoon.Adapterringsarelabeledfromthecameratothefilter.Forexample,a25.5mmto46mmstepupringisusedforacamera(orlens)with25.5mmthreads.Theadapterwillallowa46mmfilter(orotheradapterring)tofit.Adapterringscanbestacked.Tousea49mmfilterona25.5mmcameralens,firstusea25.5mmto46mmstepupringandthena46mmto49mmstepupring.Specificationofouradapterringasfollow:*M25,27,28,30,30.5,34,40.5mm,43mm,46mm,49mmto37mm*M37,40.5,43,49,55,58,62to52mm*M52,55to58mm*M55,58,62,67to72mm*M67,72,77to82mm)