Echinocactus Grusonii also goes by the names Golden Barrel Cactus, Golden Ball or Mother-in-Law's cushion (Ha!). It's a well known species of cactus, which hails from east-central Mexico.
The sharp spines are long, straight or slightly curved, and various shades of yellow or occasionally white. The stem is dark green. A mature plant can grow up to 1 metre.
The pot size is 25cm and the plant is approximately 20-25cm tall.