This Gtech CLM lawn mower battery charger is the perfect replacement for your existing battery model 121A0025. With a 36V output and 4000mAh capacity, it is compatible with GTECH mowers and ensures efficient charging. The unit is made of durable plastic and comes in black, seamlessly blending with your mower's design. Designed and manufactured in the United Kingdom, this battery charger is a reliable and high-quality accessory for your Gtech lawn mower. It is easy to use and fits most GTECH models. Keep your lawn looking pristine with this top-of-the-line battery charger.