This card is a carrier for up to four standard industryPack modules. The M-Carrier object can only be placed into a VME crate object. Double-clicking it brings up a dialog onto which you can drop one of the M-modules, i.e. the M321.

Please refer to the manual for more details.

Here's an example of a carrier that is holding one M module, the M321. M modules can be dragged to different positions on the card. When an M module is inserted into the carrier, a connection point will appear on the M carrier card in the VME crate view.