FOREND WILL NOT FIT ALL 500's RIGHT OUT OF THE BOX. This forend is designed to replace Mossberg's that have the existing 7-3/4" slide tube. That is, the existing forend is mounted on a tube which slides on the magazine tube, said tube is 7-3/4". OK now, Mossberg 500's have 3 separate ways of mounting the forend to the shotgun. First is the 7-3/4" tube, which will require nothing for this forend to work. Second, it will have a 6-3/4" slide tube which will require Hogue part # 05020 which is an adapter for the shorter slide tube. In some cases, it will also require that you grind down some of the ribs in the new forend to accommodate the adapter (the one i received had the ribs pre-ground). Third method, there is no slide tube. The forend on the shotgun is a forend/slide tube combo. This will require you buy the new factory slide tube (from some place that sells Mossberg factory parts like Brownells, Mossberg part#12362BL, Brownell's Part#631-000-295. This is for the 6 3/4" slide, as it's cheaper than than the 7 3/4" slide with the locking nut.), and the Hogue adapter. To replace the slide, you will need to completely tear down the shotgun as the slide is one of the last pieces to be removed from the receiver.
Hogue needs to do a better job informing its customers what they will need to make this package work with their shotgun, it's not like Mossberg 500's are some obscure firearm. When looking at Hogue's web support, there numerous help requests for this exact problem, and while I understand Amazon might not readily update it's product descriptions, Hogue's packaging itself makes no mention of this.
5 Stars for the product itself, 1 Star for informing the customer about what the hell is going on.