This knockbox (dump bin) from Motta completes the old barista craftsmanship experience. It is composed of a cylindrical brushed stainless steel tube.

The details:

Stainless steel tube which is closed at the bottom with a seamless weld.
No visible screws or bolts
Neoprene rubber base for a soft knock out. This protects the wrist. The rubber base reduces noise
Rubber coated edge on top of the knock box protects knock box if you miss.
Polished stainless steel – Ø 105 mm