NI PXI Express chassis incorporate all the features of the latest PXI specification, accepting both PXI and PXI Express modules. NI offers seven different chassis, featuring 4 to 18 slots, to meet your specific application needs. PXI Express chassis are the highest-performance chassis, incorporating high-bandwidth backplanes with PCI Express data communication to enable up to 50 times the system bandwidth of a PXI chassis. In addition, each chassis includes a 10 MHz and 100 MHz reference clock and trigger bus. Many NI PXI Express chassis include a timing slot for high precision and multichassis timing and synchronization capabilities.