The acclimation box is easily assembled. Comes with slide out door and lift off lid. Acclimation box has been designed to make sure your fish or coral has ample water movement thru the box. Utilizing the enclosed silicon O rings, this Single Acclimation Box comes in a flat pack and easy to build but yet very sturdy. When not required it's easily dis-assembled for compact flat storage ready for when you need it again to acclimatize your next tank inhabitants.