32 Channel Expansion Chassis for Mesa Controller. These Chassis control up to four 8×1 or 4×2 modules, or up to four 8K modules in a slightly larger 4 RU chassis. LEDs on the front panel show switch and power status. 

Dimensions:
19″ Rack Mount (483 mm)
15″ deep (381 mm)
5.25″ (3 RU) high (90 mm) but can be built as 4 RU to hold four 8K modules.
Weight: 15 to 25 lbs (7 to 11 Kg) max
AC Power : 75 Watts max. 110/220 selectable.

Link to HXV Switch Modules