Top Gear #8 DMM Boa Screwgate

DMM make several locking options but for standard climbing situations I would choose the screwgate variety every time. Screwgates are very user friendly and the physical process of screwing them closed gives time to check they are locked. They are also available in a variety of colours which makes them perfect for use in an instructional capacity (I give each client a small selection of Boas and coordinated slings with a different colour for each person so it is easy to track who is clipped in to which).