You cannot add "Cisco - QSFP+ transceiver module - 40 Gigabit LAN, 100 Gigabit Ethernet - 40GBASE-BiDi, 100GBASE-BiDi - LC multi-mode - up to 100 m - for Mellanox ConnectX-5 Ex EN" to the basket because the product is out of stock.
Cisco Business 250 Series CBS250-8P-E-2G – Switch – L3 – smart – 8 x 10/100/1000 (PoE+) + 2 x combo Gigabit Ethernet/Gigabit SFP – rack-mountable – PoE+ (67 W)