The Oval Screwgate Carabiner from DMM is the perfect anchor building and secure racking biner.
It features I-Beam construction for superior strength to weight ratio and a 16mm gate opening with a generous size that can hold a good surface area of rope without bunching.
The Oval Screwgate offers smooth handling no matter what you apply it to; offering excellent handling and load balance when used as part of a pulley system.
DMM is an awesome recreational climbing and mountaineering equipment company from Llanberis North Wales. Founded in 1981 they still make and test all their gear from home.