That could be an Elesh Norn, Grand Cenobite or Avacyn, Angel of Hope you're popping into play for the low price of 3 mana and bouncing a tapped creature back to your hand, which is possibly additional upside with the right ETB creatures
Set contents: 1 Booster Box: 36 Boosters
You can enchant your opponents massive creature, and suddenly you can totally stonewall it with a 1/1 token or 0/1 Argothian Enchantress
While I really like the Sealable Perfect Fits, as they offer an extra bit of protection by covering an edge of the card that the Perfect Fits don't, they're a lot more work to sleeve up, because you have to slide in that extra tab for each sleeve
Item is sold in 'as is' condition
The mere presence of a counter means that a card can provide a benefit or be the target of spells due to its flair, in the parlance of Office Space