Original Lenovo Thinkpad X240 X250 M.2 SSD Connector Adapter Board + Cable used | eBay
Looks like m.2 2280 worked out just fine for t450s : r/thinkpad
ThinkPad X240 upgradability? : r/thinkpad
ThinkPad X240, X250 - Hard Disk Drive and Solid State Drive Replacement - YouTube
Dual Band Wireless-AC 7260 NGFF M2 Use for Intel AC 7260NGW 802.11ac 2x2 Wi-Fi + Bluetooth 4.0 Compatible with Lenovo Thinkpad T440 T540 X240 W540 L540 L440 Fru: 04X6007