The Dell Latitude 3340 Laptop Supports Single Drive Configuration Only. (One 2.5" Solid State Drive or Hard Drive or One mSATA Solid State Drive in a Adapter Caddy) Note: When a mSATA Drive is installed, the mSATA Drive occupies the 2.5" Drive bay using a adapter caddy. The mSATA Drive uses a adapter kit p/n 4PP60 and is then Installed in the 2.5" Drive caddy p/n HKD3Y. If replacing the mSATA Drive for a 2.5" Drive, you will need to remove the caddy p/n HKD3Y from the mSATA adapter and Install it on the 2.5" Drive for Installation in the machine.