A Salamander twin impeller shower pump is perfect for boosting pressure in your hot and cold supply. This type of pump will increase each supply by the same amount so you’ll receive a powerful and equal flow to your outlet instead of having one supply that’s overly strong. These particular Salamander pumps have a bar pressure of 2.0 or less which means you’ll receive a small to medium increase. The higher the bar pressure, the bigger in boost you’ll get.