The Boa is a high volume karabiner with a large gate opening and extended top bar, making it easy to clip with thick ropes and slings, and allowing it to accommodate multiple attachments. Its asymmetric shape sits naturally in the hand for easy handling, and I-Beam construction means that despite its large size, the Boa is still relatively light.
This Kwicklock version has a double action self locking gate (ie one action to twist the gate and a second to open it).