1. High-quality ABS+PC material, strong and tough, good flame retardant performance; 2. Double-layer waterproof cover design, with very good airtightness; 3. Copper nuts are used for the outlets, and screws are required to purchase this battery; 4. Humanized carrying strap design. At the same time, the carrying strap is fixed with embedded and screw double fixing methods, which is more firm; 5. This model can hold 180 18650 batteries, 9 series 10 parallel or 10 series 9 parallel double layer, 60V20A 72V20A lithium ion battery; Colour:blue Material:ABS+PC Size:225 x 200 x 170MM internal : about 220x195x165MM Package Contents: 1 x Battery case Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.