Can someone explain to me what a flex tab kit is. Saw it in a parts listing for Remington 870 Shotgun.

The flex tab kit, is a kit offered by Remington, for use in combat situations. The kit consists of a bolt, cartridge carrier, and magazine follower. All these components have been redesigned for use in combat, primarily to prevent jamming and hang ups. As you can imagine, a jam up in the middle of combat could send things south in a hurry. I believe it comes standard on the "Police magnum" models and can be fit on the "Wingmaster", and I'm not really sure about the express model.

Hope that helps
Chad

If you have a newer 870 your shotgun already has a flex tab, turn it upside down and look at the carrier/lifter, if there is a three sided slot(box without a top) in the lifter you have the flex tab, on guns without the flex tab you can short stroke the action/ eject the empty but not get a new round, disgusting while hunting and could be fatal in combat.