Hello and thank you for contacting Fujitsu Forum Support!
The FUJITSU ESPRIMO Q556/2/D, featuring full desktop PC functionality in a stylish and compact mini PC, is a real eye-catcher on your desk. Unfortunately, but the D3403 ESPRIMO Q556 (with D3403) has only the M.2 module for M.2 WLAN 802.11ac (2x2) and BT 4.1 (dedicated regions only, up to BT 4.2 depending on OS version).
But depending on your specific product, there may be possibility of using the PCIe SSD modules and one 2.5'' HDD. Please see the page 61 of the expansion options in Operating Manual, here:
https://support.ts.fujitsu.com/IndexDow ... 06766A2112 or attached to this call.
Best regards,
Fujitsu Forum Support