For a queen-size Murphy bed with a standard mattress, you’ll want to choose the appropriate gas piston to ensure smooth operation. Based on the lifting capacity, here are the options: 110 - 130 lbs Lifting Capacity: The Hafele 271.92.265 Gas Piston falls within this range. However, since it didn’t work for you, let’s explore other options. 125 - 140 lbs Lifting Capacity: Consider the Hafele 271.92.266 Gas Piston with a slightly higher capacity. 135 - 150 lbs Lifting Capacity: The Hafele 271.92.267 Gas Piston provides additional strength. 145 - 160 lbs Lifting Capacity: If you need more power, go for the Hafele 271.92.268 Gas Piston. 155 - 170 lbs Lifting Capacity: For seamless opening and closing, the Hafele 271.92.269 Gas Piston might be the best choice. Remember to consider the weight of the mattress, bedding, and any additional front panels when making your selection.