Lens hoods are primarily designed to prevent unwanted stray light from entering the Lens by extending and shading the Lens' end. Besides, since the Lens' end is grown, you also benefit from some extra protection from accidental impact.
Features:
Designed to prevent unwanted stray light from entering the Lens
Ensures no problems with vignetting or motor functions
The added benefit of extra protection from accidental impact
Compatible with TS-E 45mm f2.8 lens
Specifications:
Designed for: TS-E 45mm f/2.8
SKU: 2682A001
UPC: 082966440854
Package Weight: 0.135 lb / 62 grams
Box Dimensions (LxWxH): 4.7 x 4.5 x 1.55 inchs
Kit content Canon EW-79BII Lens Hood for TS-E 45mm f/2.8 Lens User guide
For more information about, Canon EW-79BII Lens Hood for TS-E 45mm f/2.8 Lens website.