This is massive and majestic! A solid brass, antique door knocker. I've seen smaller, lighter replica ones of similar design on the Copper Mountain Hardware website. Massive 5 lb, 4 oz weight.
From the look of it/hardware, you'd need to drill a hole through your door to anchor it. Has a beautiful, patina to it. I think the small plate is the online contact point for the knocker. In one picture, is shows it on back screw, which might not be it's placement. In that case, itd need hardware for small plate (aka screw, nail).
Measurements:
LION PART
Length: 5 1/2"
Width: 4 1/4"
KNOCKER PART
Width: 5 3/4"
Length: 5 1/2" roughly
SMALL PLATE
Width: 1 3/4"
Depth: 5/8"
Total Length: 9"
Depth: 1 3/4"
Weight: 5 lbs, 4 oz
Screw length total: 3"
Screw head: 1/2"
Screw diameter: 3/16"
If you have any questions, please feel free to ask!
Product code: ANTIQUE MASSIVE BRASS Door Knocker/ Lion online Head