My PW131 Model Overview from PartSelect.com

Quick Connect Fitting With Water Stop – Part Number: PM020600SV

Part #PM020600SV

Genuine Manufacturer Approved replacement part designed for use with some Campbell Hausfeld Pressure Washers. This part is made out of Plastic and it is Sold Individually. This Adapter connects to the Pump allowing for the water to flow. Note: This needs part number PM022100AV to work

Nipple Adapter

Part #PM022100AV

Genuine Manufacturer Approved replacement part designed for use with some Campbell Hausfeld Pressure Washers. This part is made out of Plastic and it is Sold Individually. This Adapter connects to the Pump allowing to for the water flow.

O-Ring

Part #PM232200SV

This is an authentic manufacturer-sourced replacement part which is designed for use with Campbell Hausfeld pressure washers. It helps to provide an air tight seal for the lance, over time the o-ring may begin to deteriorate and crack eventually requiring replacement to maintain the proper seal. It is a high-quality component which is made of durable rubber and it is sold individually.