The Makita 18Vx2 Brushless Battery Backpack Adaptor 191A626 comes standard with an 18V and 18Vx2 adaptor allowing it to be compatible across the entire Makita lineup. It has 4 battery slots inside and will provide up to 4 times longer runtime. The comfortable backpack harness provides maximum comfort and with the adaptors replacing the battery in the tool, the tool weight is significantly reduced minimizing fatigue. It also features a convenient battery fuel gauge on the outside to keep track of how much battery life you have left.

Main unit ? holds 4 18V Li-ion batteries, which are installed to power both 18V and 18Vx2 tools

Battery fuel gauge ? indicates the power remaining in each battery individually in 2 stages

Versatile backpack harness ?the comfortable backpack harness allows for use for long periods of time with minimal user fatigue. Harness can also be detached from battery box to be used as a stationary power pack

Adaptors ?transfers the power from the main unit to the tool body, without the weight of the batteries. Provides the ability to be used on both 18V and 18Vx2 tools.

• Develop a battery adaptor that assists in reducing the weight transferred to the users arms and hands whilst providing improved tool runtimes
• Designed to reduce user fatigue, by transferring battery weight
  from the tool body to the back, allowing longer periods of use.
• Compatible across entire range, comes with 1x 18V & 18Vx2 adaptor
• Pivoting adaptor increases tool maneuverability
• Lightweight design at only 7kg with 4x 6.0Ah batteries
• Comfortable, adjustable backpack harness
• Convenient battery fuel gauge

Advantages: 

• Ability to power both 18V and 12Vx2 Tools
• Innovation 36V (18Vx2) Technology
• Convenience: Ability to check remaining battery life from outside the backpack
• Efficiency: Pivoting cord increases tool mobility

Specifications:

• Battery fuel gauge: Yes (2 stage)
• USB port: No
• Overall length: 400mm
• Skin weight: 4.4kg
• Weight (with battery): 7.0kg
• Battery is not included.