BTDCM4.2 is a high quality battery from Optima. The cold cranking current of the battery is 765 A. The dimensions of the product are 254 x 175 x 200 mm. You should use the dimensions of your old battery as a guide for your selection. Durable AGM technology for your vehicle The BTDCM4.2 has a capacity of 55 Ah. The higher the value, the more electrical charge can be stored in the battery. AGM batteries like the BTDCM4.2 are suitable for marine dual use with high energy requirements. They have a long cyclic life. The technology of this battery covers the dual starting and supply requirements of marine systems. You should consider this when buying Before you buy, check that the circuit and polarity of your new battery are identical to the values of the old model. The circuit shows whether the positive pole is on the right or left of the battery. To determine this, position the battery so that the poles are facing you. With the BTDCM4.2, the circuit is 1, so the positive pole is on the left.