Lenovo Thinkpad T450s Business Laptop, Intel Core i5-5th Gen. CPU, 8GB RAM, 256GB SSD, 14 inch Touchscreen, Windows 10 Pro
Looks like m.2 2280 worked out just fine for t450s : r/thinkpad
Amazon.com: Lenovo ThinkPad T450 14in HD Business Laptop Computer, Intel Dual-Core i5-5300U Up to 2.9GHz, 8GB RAM, 128GB SSD, HDMI, 802.11ac WiFi, Bluetooth, Windows 10 Professional (Renewed) : Electronics
Lenovo ThinkPad T450 i5 5300U 8G 128G SSD 14" HD+ W11 Pro CAM Wi-Fi BT - Grade A | eBay
Upgrading a ThinkPad T450s with an M.2 SSD - James Ridgway
Amazon.com: Lenovo ThinkPad T450 14in HD Business Laptop Computer, Intel Dual-Core i5-5300U Up to 2.9GHz, 8GB RAM, 128GB SSD, HDMI, 802.11ac WiFi, Bluetooth, Windows 10 Professional (Renewed) : Electronics
Lenovo ThinkPad T450 14in HD Business Laptop Computer, Intel Dual-Core i5-5300U Up to 2.9GHz, 8GB RAM, 256GB SSD, HDMI, 802.11ac WiFi, Bluetooth, Windows 10 Professional (Reused) - Walmart.com
Lenovo ThinkPad T450 14" Laptop PC Intel Core i5-5300U 5th Gen 2.3GHz 8GB Ram
Lenovo Thinkpad T450 Hard Drive/SSD Replacement - YouTube
Lenovo ThinkPad T450 Thin Laptop PC 14", Windows 10 Professional 5th Gen Intel Core i5 with 8GB 256GB SSD VGA Mini DisplayPort USB 3.0 - Used Laptop Notebook For School - Walmart.com
How to Install SSD and Ram Upgrade in Lenovo ThinkPad T450 Laptop - YouTube