Cliff Keen Ultimate Sock. The only sock you'll ever want to wear while officiating.Introducing the Ultimate Officiating Sock from Cliff Keen! Reinforced toe and heel. Comfort-fit stretch over the arch. Elastic strength to the top of the calf. It's the most comfortable sock in the officiating industry. Wash and wear durability for an entire season's worth of assignments with no shrinkage or discoloration.