Sigma rear sight laser by Laserlyte

[zeroed_in]

hey team,
i was wondering if anyone has any experience w/ this rearsight laser. i went to laserlyte's website but i couldn't find this product on thier page.

LASERLYTE REAR SIGHT LASER S&W SIGMA SW9VE SW40VE - LLRL-VE

 

[speedyquad]

i considered purchasing one of those, just not sure how well the battery and laser tubes would affect the sight picture.