Choate Machine & Tool's MK5 Remington 870 Conventional Stock features a new spacer system which was originally designed for the police for use with body armor; however, they work great for the hunter and recreational shooter as well. These stocks come with two 1/2" spacers included which adjusts the length of pull from 13" to 14".You can lengthen your stock by simply adding new spacers and longer screws.