Have a look into this thread:
On the other hand if I remember correctly the WLE1216V5-20 has a metal thing on its back which does not fit into slot 3 as there sits the SIM-card-slot. It’s a pity the SSD can only be installed in slot 1 
Have a look into this thread:
On the other hand if I remember correctly the WLE1216V5-20 has a metal thing on its back which does not fit into slot 3 as there sits the SIM-card-slot. It’s a pity the SSD can only be installed in slot 1