Standard 1/4" QC Plug. Plugs in at either the end of your lance or at the spray gun.
Used with KEW style coupler. Plugs directly into the spray gun for a detachable lance setup.
If you are looking to thread the ST-75s directly onto a lance for a dedicated foam lance set up.
For use with hot water machines it is recommended to swap out the agitator pad periodically. Most issues with a foamer are related to the agitator pad getting clogged with coil scale or debris in the water.