Maintenance-free quality batteries at an interesting price. For ship propulsions or general use in modelling, as well as to start internal combustion engines, with GRAUPNER electric starters. The batteries are electrolyte leak-proof, position-insensitive & have flat-pin plug contacts, suitable for FASTON-flat-pin plug sockets 4.8 mm. Rechargeable with multiple charging devices MULTICHARGER, mc-ULTRA-CHARGER or AUTOMATIC CHARGER PB.