Rubber extendible lens hood

[ymc226]

I have a present version Summicron 75/2.0 which takes a 49mm filter (has filter on). Rather than using the built in lens hood which I am paranoid may get damaged, anyone use a rubber extendible lens hood (generic) 49mm.

http://cgi.ebay.com/49-49mm-3-Stage...ryZ78999QQssPageNameZWDVWQQrdZ1QQcmdZViewItem


Will this cause vignetting?

 

[Benjamin]

If it costs $6, why don't you just try it out dude?