The TwinLock, further expands the range of fully automatic quick couplers offered by Miller. In light of current concerns regarding semi automatic quick couplers, the TwinLock has been designed to enhance on-site productivity but with optimum safety. It features a new shaped jaw and two non-hydraulic safety devices designed to minimise the risk of operator misuse and maximise on-site safety pertaining to attachment pick up, release and general operation. It is the only pin pick-up quick coupler in the world to incorporate this unique twin back up safety system, hence the name - TwinLock.

The first safety mechanism, the front latch, locks the front bucket (or attachment) pin into position during both the attach and release process (until the required release step is reached). The bottom portion of this latch remains in position over the bucket pin so that correct engagement can be visually verified from the cab. In the unlikely event of loss of engagement forces to the coupler hook the front latch falls back into position to fully lock in the front pin.

The second safety mechanism comprises two mechanical stops which operate in unison. Under gravity these fall into position behind the extended coupler hook to ensure that in the unlikely event of loss of engagement forces the attachment cannot be inadvertently released.

An additional and unique feature, the retaining jaw, has been designed to provide a reliable way to release a bucket or attachment, as it is only possible to disengage in a safe and controlled manner.