A coupling to attach a device such as an infant seat to an anchor member. One version of the coupling is characterized by a frame having a mouth with a seat configured to receive the anchor member and a lever movably mounted on the frame to hold the anchor member inside the mouth. The lever has a downwardly projecting finger that blocks the mouth of the notch in the closed position and allows access to the notch when moved to the open position. The coupling may include a stop member to resist movement from the closed to the open position. The coupling also may include a web adjuster or other connecting device operatively disposed between the coupling and the device.