An agricultural planter includes a chassis； a pneumatic system carried by the chassis； and a row unit carried by the chassis. The row unit includes: a unit body； a metering unit carried by the unit body and having a port with a channel formed therein； a flexible coupling locked onto the port by an inner lip formed on an inner surface of the coupling, the coupling having a sliding region formed on an outer surface of said coupling； a locking ring bound within the sliding region of the coupling, the locking ring being slidable across the sliding region between a locked position and an unlocked position, the locking ring preventing the coupling from deforming to allow the inner lip off the port in the locked position； and a hose connecting the pneumatic system to the channel of the port through the coupling.
