Lifting attachment for lifting containers

A lifting attachment, comprising:

• a lifting attachment frame, and
• an arm on each end of the lifting attachment frame, wherein the arm comprises an upper locking mechanism configured to graban upper container and a lower locking mechanism configured to grab a lower container, the upper locking mechanism being at a first end of the arm and the lower locking mechanism being at a second end of the arm opposite the first end, wherein the arm is configured to lift the upper and lower containers simultaneously, wherein each arm further comprises a pivotable extension provided at the second end of the arm next to the lower locking mechanism and connected to an actuator, wherein a proximal end of the extension comprises a pivot point connecting the extension to the arm and a distal end of the extension comprises a support portion, wherein in a resting position the distal ends of the extensions are turned to move the support portions closer to each other and in an operating position the distal ends of the extensions are turned downwards for supporting the lower container from its longitudinal side.