lenovo 4d slot

Slot 3: half-length full-height (length 189mm, height 104mm), PCIe 3. aviator slot 0 x1* Slot 4: no slot, only bracket for optional port extension* M 2 card slots: Two (one for WLAN, one for SSD/Optane) * Optional 2 front USB3 1 Type-C ports module occupies PCIe x16 slot (x4 card), optional rear 2x USB2 0 / parallel occupies one expansion slot