A retainer apparatus including a first retainer portion, a second retainer portion, a transceiver, and a sensor comprising a motion detector. The retainer apparatus includes the first retainer portion configured to be slidably attached to a first harness strap and a second retainer portion configured to be slidably attached to a second harness strap. The first retainer portion is removably attached to the second retainer portion. The motion detector is configured to detect movement of the retainer apparatus and transmit a warning signal, via the transceiver, to a controller within a vehicle comprising the retainer apparatus to alert a user in the vehicle if the movement is detected.

A retainer apparatus including a first retainer portion, a second retainer portion, a transceiver, and a sensor comprising a motion detector. The retainer apparatus includes the first retainer portion configured to be slidably attached to a first harness strap and a second retainer portion configured to be slidably attached to a second harness strap. The first retainer portion is removably attached to the second retainer portion. The motion detector is configured to detect movement of the retainer apparatus and transmit a warning signal, via the transceiver, to a controller within a vehicle comprising the retainer apparatus to alert a user in the vehicle if the movement is detected.

A harness apparatus including a first adjustable harness strap, a second adjustable harness strap, and a retainer apparatus. The retainer apparatus includes a first retainer portion slidably attached to the first harness strap, a second retainer portion slidably attached to the second harness strap, and a braking mechanism configured to prevent the first retainer portion and the second retainer portion from moving along the first harness strap and the second harness strap. The first retainer portion is removably attached to the second retainer portion. The braking mechanism includes a braking device configured to apply resistance to the first harness strap and/or the second harness strap and to hold the retainer apparatus in a stationary position along the first harness strap and the second harness strap.