These containers are as strong as a plywood crate, but at the cost of corrugated. features: perfect for shipping heavy items such as small motors, compressors or valves constructed from 1100# tw/ect-90 corrugated kraft additional thickness provides extra protection, security and stability during shipment rsc = regular slotted container sold in bundle quantities of 5 the dimensions are the inside dimensions of the product for help selecting the right box, click the brochure tab below.