Built for medium to heavy duty trucks, Buyers Products Heavy Duty Diamond Tread Aluminum Step Box provides framed steps with convenient built-in storage space. These boxes are a great multi-purpose solution for larger vehicles like Class 8 trucks. The durable design incorporates a smooth aluminum body with a diamond tread aluminum door for great stability and looks. A die cast, locking T-latch and single rubber D-bulb door seal help keep your tools protected from weather and theft. Corner gussets and a continuous hinge on the door opening provide extra strength. Available in multiple sizes to suit a variety of applications.