The silicone strips on the strap go to the inside to help hold the strap in place. The strap doesn't require hardware to install. Simply push the ends through the slot in the mask.
There's probably two sets of screws left over from mounting hard ears to the lower half of the mask or someone didn't have the correct ones an improvised. There's a link in my sig to a thread about replacement softear hardware. Post pics for more info.
Softears mount like this...
