Mammoth Drinkware Accessories Standard Collar for Mammoth 12 oz. Chillski $4.99 Tumbler Flip Clear Lid for Rover 20 oz. $5.99 Tumbler Flip Clear Lid for Rover 30 oz. $5.99 Tumbler Lid for Rover 12 oz., 20 oz. and 22oz. $4.99 Tumbler Lid For Rover 30 oz. and 32 oz. $4.99