Shotgun ammo question

[jumpingjackflatch]

I have had this box of 12 gauge Remington shotgun shells forever (30 plus years). I don't even remember where I got them from. I am a handgun and .22 rifle shooter, so I have very little experience with shotguns.
They are marked 2-3/4 - 1-1/8 - 8 RXP. Can someone explain the nomenclature and what these would be used for? They have been stored in a dry cupboard and seem in perfect shape. Would they still be usable?

 

[iceman2]

2-3/4" long (after fired) 1-1/8 ounce of #8 shot. Most likely clay shooting most probable use. They could be used for upland game hunting also. If kept dry as you said good to go.