What you'd use it for
A Bank Shell turns loose Double Rainbow tubes into one rigged soft source: a hard shell with an Ossium plate on the back, an Ossium Baby Pin for mounting, and the fixtures supplied in the kit. Because a Double Rainbow is twice the width of a single row tube, a 2-Bank shell holds one Double Rainbow and a 4-Bank shell holds two. Check that before you order, because the bank count describes the shell, not the number of fixtures.
Configuration sets the tube length and the shell size together. A 2-Bank shell takes one Double Rainbow, a 4-Bank shell takes two, so the 4-Bank kits carry twice the fixtures and add a multibank power adaptor.
Figures published by Quasar Science.