DMM have issued a product recall notice, subject to user inspection, to Total Access (UK) Limited affecting a limited range of DMM manufactured karabiners.
The problem affects the gate closing mechanism in a small percentage of karabiners and can be easily identified by inspection.
Please follow the link http://dmmprofessional.com/documents/dmm-product-recall-14-09-2015.pdf to the DMM Product Recall Notice for guidance on identifying affected karabiners.