Brompton introduced the rear frame clip in 2007. Now pre-2007 models can be upgraded with this kit adding this feature. The rear triangle clips into position to stop it unfolding when lifted. The rear frame clip assembly can be set in latch mode or non-latch mode.In latch mode the clip automatically engages with the rear frame when it's unfolded, so that the rear frame/wheel doesn't fold when your Brompton is lifted. In non-latch mode the clip can't engage, leaving the rear frame free to fold and allowing easier parking.