item is a used industrial pump, specifically a Balcrank (or Wilden) M2 316 stainless steel air-operated double diaphragm pump. 

• Material: Constructed from 316 stainless steel, suitable for chemical processing and industrial applications. 

• Capacity: Generally features a 1-inch (25mm) inlet/outlet diameter. 

• Operation: Pneumatic (air-operated) pump designed to handle various fluids, including thick pastes. 

• Pricing: Used models are typically listed between $400 and $800 depending on condition.