laser bore sight

Anyone use one of those laser zeroing cartridge things? The only ones I can find online are Chinese with very varied reviews. If any good, I wouldn’t mind paying more for something better.

Private sale 1 x sightmark .30-06/ .25-06 etc laser bore-sighter with original box (opened) With 1 x generic .243/.308 laser bore sighter boxed (opened) Both with batteries £35.00 posted for the pair