Application notes for Benelli M4 shotguns:   the Benelli M4 two shot extension replaces the factory shell limiter on the M4.  The limiter is the coil spring looking area on the M4 factory tube.  Replace the factory limiter with the Nordic M4 two shot extension to gain two extra rounds without adding length to the tube.  If further round capacity is needed, replace the barrel nut cap with the Nordic Benelli Nova tube desired for even more capacity.  The +1 tube is the most popular tube in this case, as the M4 two shot extension used in combination with the +1 Nova tube increases the capacity in your M4 by 3 additional rounds.  Note:  due to a problem with M4 tubes, they are not being shipped at this time.

Application notes for all pump shotguns:  many tactical type pump model shotguns comes with a 8 plus 1 capacity, and while they will hold 8 shot shells in the tube, they will not hold 8 slugs in the tube.  Use the +1 tube extension to get 8 slugs in the tube for 8 plus 1 slug capacity.

Nordic extension tube assembly length (includes barrel nut in measurement):

Winchester SX2/SX3/Browning Gold +2 - 5.76"

Winchester SX2/SX3/Browning Gold +5 - 11.60"

Winchester SX2/SX3/Browning Gold +8 - 19.82"

Benelli Nova/Beretta Extrema +1 - 3.21"

Benelli Nova/Beretta Extrema +2 - 5.89"

Benelli Nova/Beretta Extrema +3 - 8.42"

Benelli Nova/Beretta Extrema +4 - 10.19"

Benelli Nova/Beretta Extrema +5 - 11.73"

Benelli M1/M2/SBE +4 - 10.47"

Benelli M1/M2/SBE +5 - 12.01"

Benelli M1/M2/SBE +7 - 17.62"

Benelli M1/M2/SBE +8 - 20.23"

Benelli M4 +2 - 5.89"

Remington 870/1100/11-87 +4 - 10.05"

Remington 870/1100/11-87 +5 - 11.59"

Remington 870/1100/11-87 +7 - 17.20"

Remington 870/1100/11-87 +8 - 19.81"

Mossberg 590/835 +1 - 3.28"

Mossberg 590/835 +2 - 5.96"

Mossberg 590/835 +3 - 8.49"

Mossberg 590/835 +4 - 10.26"

Mossberg 590/835 +5 - 11.80"