Poor quality - G-Sight Laser Bore Sight

I would like to be writing a positive feed back however after buying 11 of the different calibers and spending hundreds of dollars on these sights, I would not recommend then the main issues consistently with all them is the light fades with in less than two minutes from the time you insert into the chamber. This may be to over heating but seems to be an across the board issue. Optics Planet has been great with delivery and standing behind these cheap bore sights. They even replaced a few for me and I had the same problem, so now the only thing these get used for are paper weights, don't waste your money on these.