This is a great solid rail system! It allows for plenty of mounting room and is strong enough that you don't break it when it is carelessly dropped. Can be a pain to put on if not used to upgrading your air soft gun. But still adds a great feel and look to any gun.
Solid fit that doesn't turn or wiggle then in use.
Adds realistic feel
easy to mount things to
Can be a pain to put on.
makes some guns heavier
some people may find the rails an uncomfortable feel in the hand.