Based on this product's specifications, here are some alternatives and similar models
Battery POLY CS540 Black 85Q98AA Reliable Power Longevity
Summary description:
The POLY CS540 Battery is designed for optimal performance in compatible devices. With a sleek black design, it offers reliable power and longevity, ensuring your devices stay operational for longer periods. Ideal for professional use, this battery is a perfect replacement for your existing POLY CS540 battery.