Lot of (300) indented hex washer head outdoor wood screws with a 1/2" diameter bonded EPDM neoprene 304 stainless washer.
These Strong-Shield coated fasteners are #10 thread and are 1-1/2" in length with a type 17 tip and 1/4" hex drive.
The type 17 tip is a thread cutting screw for wood with an auger style point that helps clear chips and reduce splitting.
Designed to attach metal panels to wood in roofing and siding applications.