Feyachi BoreSighter Bore Sight kit for 0.22 to 0.50 Caliber Rifles Handgun Red Laser This item is Light Designed,it come with 5 adapters and can fits calibers from 0.22 to 0.50. Simply choose the caliber adapter and place the laser unit in the muzzle.Allows for quick and accurate resets sight. The sight will emit a straight red laser beam, providing a precise reference for zeroing in on your target. This laser boresighter is easy to use and will quickly save both time and money by avoiding prolonged live fire tests at the range. This is a updated Item: The previous one is come with Rotary switch.And the updated one is Button switch.The quality is better than before.