Often, if you have many accessories mounted, you need counterweights to balance the OTA of your Dobsonian telescope. Farpoint's 1.5 pound magnetic bag weight sticks securely to the steel OTA of many solid tube Dobsonians. The Cordura bag contains 1.5 pounds of lead shot heat-sealed in plastic. The extra strong Neodymium magnets allow you to place the weight exactly where you need it to perfectly balance your dobsonian. If you need more weight, you can add Farpoint's FZ300 and FP315 stainless steel counterweights. But with or without additional steel weights, you will find that the FBW1.5 magnetic bag weight is perfect for making fine balance adjustments. When you swap the eyepiece you are using for an eyepiece of a different weight, just slide the FBW1.5 up or down on your OTA to restore your perfect balance!