This model has been discontinued by the manufacturer. I'd recommend the Bushnell Equinox Z2 4.5x40mm Digital Night Vision Monocular, which will allow you to effectively view objects up to 900 feet away in night mode when the infrared illumination level is set to high. You can find the monocular by using the link below:
https://www.opticsplanet.com/bushnell-equinox-z2-4-5x40mm-digital-night-vision-monocular.html
This Monocular has been discontinued by the manufactorer. We do carry the Bushnell Equinox Z2 3x30mm Digital Night Vision Monocular, which has a fixed 3x magnification, and can be found by using the link below:
https://www.opticsplanet.com/bushnell-equinox-z2-3x30mm-digital-night-vision-monocular.html
There are no crosshairs.
Up to 750ft viewing with infrared illuminator.
This has a rail integrated into the monocular but does not have a mount to attach to a rifle.
Thats very dependent on the quality of the battery, the amount of use, whether the illuminator is used and how often its used. Battery life can range from a few hours to upwards of 12 hours, but Bushnell does not provide an approximate battery life because of the many variables that will affect battery life.
This is a digital device that provides a black and white image.
As long as you order item 260140MT with the picatinny mount, you can use this as a clip-on night vision device. As far as front of behind the optic, that will depend on the type of optic you are using. If you are using a night vision compatible red dot sight, then it would go behind it (between the red dot and your eye). However, if you are using a traditional scope, then it would go in front of the scope.
Unfortunately, this product is not able to be ordered in any other color at this time.
Unfortunately Bushnell does not sell the mount separately.