Having a spare bean hopper on hand is never a bad idea! All hoppers fit all models of HLF machines.
Choose between the 3 sizes:
.35kg (comes standard on the 1700 model)
.65kg (comes standard on the 2700 model and as 1 of 2 hoppers on the 3700)
1kg (comes standard on the 3700 model as 1 of 2 hoppers)
 
Small Hopper and Lid .35 kg 2MK9PCOC0319, 2MK9PCPC0322
Medium Hopper and Lid .65 kg 2MK9PCOC0322, 2MK9PCPC0322
Large Hopper and Lid 1 kg 2MK9PCOC0325, 2MK9PCPC0326