▁ground ▁and ▁the ▁sensor ▁easily ▁uns cre wed . ▁If ▁it ▁was ▁de emed ▁necessary ▁to ▁render ▁the ▁mine ▁completely ▁in ert , ▁three ▁pl ugs ▁on ▁the ▁top ▁granted ▁access ▁to ▁the ▁three ▁det on ators ▁inside ▁the ▁mine . ▁These ▁could ▁be ▁uns cre wed ▁and ▁the ▁det on ators ▁removed . ▁ ▁In ternal ▁components ▁The ▁following ▁diag rams ▁show ▁the ▁SM i - 3 5 ▁mine ' s ▁internal ▁mechanism , ▁together ▁with ▁the ▁three - pr ong ed ▁pressure ▁f use . ▁The ▁safety ▁pin ▁for ▁the ▁f use ▁and ▁the ▁three ▁remov able ▁pl ugs ▁for ▁the ▁det on ators ▁are ▁clearly ▁visible . ▁These ▁diag rams ▁were ▁issued ▁as ▁part ▁of ▁a ▁US ▁Army ▁field ▁manual ▁on ▁mines ▁in ▁ 1 9 4 3 . ▁ ▁Im itations ▁ ▁The ▁S - mine ▁was ▁an ▁extremely ▁successful ▁design . ▁B ounding ▁mines ▁based ▁on ▁its ▁design ▁were ▁introduced ▁by ▁other ▁countries . ▁ ▁The ▁Finn ish ▁army ▁began ▁purch asing ▁the ▁SM i - 3 5 ▁model ▁S - mine ▁from ▁Germany ▁following ▁the ▁Winter ▁War . ▁This ▁was ▁part ▁of ▁a ▁larger ▁military ▁assistance ▁agreement ▁between ▁the ▁two ▁nations . ▁Finn ish ▁forces ▁experienced ▁great ▁success ▁with ▁the ▁S - mine , ▁but ▁its ▁mon et ary ▁cost ▁was ▁considerable . ▁During ▁the ▁Cont inu ation ▁War , ▁the ▁Fin ns ▁un success fully ▁attempted ▁to ▁produce ▁their ▁own ▁version ▁of ▁the ▁mine . ▁The ▁Finn ish ▁nick name ▁for ▁the ▁mine ▁was ▁Hy ppy