Dear friend, the verify of coffee bean grinder is a obligatory process, and it is normal to have espresso powder residue. Hope to get your variety understanding. Upgraded Stepless AdjustmentModel: ITOP40SVolatge: 220V~240V/50Hz~60Hz; 110V/60HzPower: 150WBean Hopper Capacity: 75GMotor Speed: 550R/MConical Burrs: 40MMMaterial: Aluminium alloy body + Titanium burrPowder Cup size: φ52mm*H90MMMachine size: 11*17*37cmMachine weight: 3