Reduced barrel clamp for ga.20 in polymer

Marocchi A20 cal. 20 - Marocchi SI 20 cal.20 - Benelli M1 20 cal. 20 - Benelli M2 20 cal. 20 - Benelli M2 Camo 20 cal. 20 - Benelli Nova 20 cal. 20 - Benelli Nova Camo 20 cal. 20 - Franchi Affinity One cal. 20 - Franchi Affinity Black Synt cal. 20 - Franchi Affinity Apg cal. 20 - Franchi Affinity Compact Black Synt cal. 20 - Franchi Affinity Wood cal. 20 - Franchi Affinity Max 5 cal. 20 - Franchi Affinity Compact Max 5 cal. 20 - Marocchi ATA 20 cal. 20 - Winchester SX3 Field Black Shadow cal. 20 - Winchester SX4 Composite cal. 20 - Winchester SX4 Field cal. 20 - Winchester SX4 Camo Mobu cal. 20 - Winchester SX4 Water Fowl cal. 20 - Beretta A400 LITE Sintethic cal. 20 - Beretta A400 LITE Camo Max cal. 20 - Beretta A400 LITE Compact cal. 20 - Browning Fusion Hunter cal. 20 - Browning Gold cal. 20 - Bernardelli Mega cal. 20 - Bernardelli Mega Cigno cal. 20 - Bernardelli Mega Syntethic cal. 20 - Bernardelli Mega Camo cal. 20 - Bernardelli Mega Syntethic Slug cal. 20 - Verney-Carron V20N cal. 20 - Benelli M2 Black cal. 20 (Gen.2 Post 2023) - Benelli M2 Pro Max 7 cal. 20 (Gen.2 Post 2023) - Black Eagle III cal. 20