Lucy stock adapter dramatically increases the number of butt stocks that can be used with 20 gauge Remington 870/1100/1187 shotguns. Attached at the receiver in place of a standard 20 gauge stock, this cast steel adapter enables the use of a 12 gauge Remington 870 stock. There are many more 12 gauge stocks to choose from than 20 gauge, including Mesa Tactical’s Urbino stock.