An agricultural planter includes a chassis； a pneumatic system carried by thechassis； anda row unit carried by the chassis. The row unit includes: a unit body； ametering unit carried bythe unit body and having a port with a channel formed therein； a flexiblecoupling locked ontothe port by an inner lip formed on an inner surface of the coupling, thecoupling having a slidingregion formed on an outer surface of said coupling； a locking ring boundwithin the slidingregion of the coupling, the locking ring being slidable across the slidingregion between a lockedposition and an unlocked position, the locking ring preventing the couplingfrom deforming toallow the inner lip off the port in the locked position； and a hose connectingthe pneumaticsystem to the channel of the port through the coupling.
