Traditional style spy holes  from Carlisle Brass. 

Features:
1) Plastic Lens OR Glass Lense
2) 180 Degree View Angle
3) Rust Proof
4) To suit 34-54mm Doors
5) Suitable for Exterior Doors

Dimensions:
Tube : 13.5mm

Available finishes:
1) Polished Chrome
2) Polished Brass
3) Satin Chrome