GM12SG: 12 gauge shotgun 13 Piece cleaning kit Includes: Custom GunMaster® case, hybrid multi-function handle, 33" pull rod, one 12 gauge brush) 12 gauge mop., one 12 gauge. slot tip, 25 cleaning patches, six piece bit set (2 phillips, two flat heads, one star and one hex).GM20SG: 20 gauge 13 Piece shotgun cleaning kit Includes: Custom GunMaster® case, hybrid multi-function handle, 33" pull rod, one 20 gauge brush) 20 gauge mop., one 20 gauge. slot tip, 25 cleaning patches, six piece bit set (2 phillips, two flat heads, one star and one hex).