Welcome to Defender Canada! 
Whitecap Clamshell Ventilator Item # 1780363
Description
Specifications:
- Material: 304 stainless steel
- S Dimensions (L x W x H):4" x 3 3/4" x 1 5/8"
- M Dimensions (L x W x H): 6 3/16" x 5 7/8" x 2 3/4"
- L Dimensions (L x W x H): 7 5/8" x 6 7/8" 2 13/16"
- Fasteners (not included):
- S: (3) #6 screws
- M/L: (5) #10 screws