Expansion Chassis for use with Mesa Controller. These Chassis controls up to sixteen 8×1 modules, thirty two 4×1 modules or any combination or configuration of 8×1’s, 4×1’s, 2×1’s and 2×2 modules. LEDs on the front panel show switch and power status. 

Dimensions:
19″ Rack Mount (483 mm)
15″ deep (381 mm)
7″ to 10.5″ (4 to 6 RU) high (180 to 270 mm)
Weight: 15 to 25 lbs (7 to 12 Kg) max
AC Power : 100 Watts max. 110/220 selectable.

Link to switch module selector