Mirrodin Besieged Six-card Booster Pack has variants:
Explore this pack in Sealed.

Sheets

Sheet basic

At rate 1/10 (10.0%)

Sheet common

At rate 1/60 (1.67%)

Sheet uncommon

At rate 1/40 (2.5%)

Sheet rare_mythic

At rate 1/40 (2.5%)
At rate 1/80 (1.25%)