ISeeInHD posted a question about the +1 round extension for Remington 870 Magpul Edition on Remington 870 Forum. jdinny posted picture of his 870 with Wilson Combat (Scattergun Technologies) plus one round extension:

Wilson Combat (Scattergun Technologies) Magazine Extension for Remington 870 Magpul Edition

Wilson Combat (Scattergun Technologies) Magazine Extension for Remington 870 Magpul Edition

This magazine extension is flush with the length of the barrel.

Recommended Product:
Wilson Combat (Scattergun Technologies) Magazine Extension

Wilson Combat (Scattergun Technologies) Magazine Extension

Get +1 Magazine Extension on Brownells