Here's what other sites are saying:
Omega Pacific Climb 1/2 ''d'' Sg Black Nfpa OP12S55LNFPA. At a rated strength of 72 kN it's one of the strongest carabiners in the world Heat-treated half-load tested (over 8000 lbs.) and built to exacting standards the Steel Standard D is one very fine steel carabiner. Specifications: 1 kN = 225 lbs of force Strength Closed: 72 kN 124.5mm L x 70.6mm
The Omega Pacific(R) steel locking carabiner is designed for rescue work, caving and other heavy-duty applications.
Large D shape for great handling. Huge gate opening and massive strength of 72kN. Heat treated and individually tested. Also comes in tactical black. SG-screw gate. 3AL-three-stage auto-lock. New for 2011 are key lock gate versions. Weight: 283 grams Strength: 72kN 1/2" steel bar stock Plated to increase corrosion resistance NFPA Certified UL Classified G
- Vargo Outdoors
The Omega Pacific Steel Large D Screw-Lock Carabiner is obnoxiously strong, period. Towing your jet' Hauling a train full of elephants' Taking a lead fall with 10 of your closest friends following behind' With a strength-rating of 72kN, the Large D has bragging rights as one of the strongest carabiners on the planet. Whether your gear and hauling needs demand it, or you just like having your life backed up by big numbers, dangling one of these babies from your harness lets everyone know you aren't messing around.
Omega Pacific 1/2" Standard D NFPA Screw-Lok
Omega Pacific G-First NFPA Screw-Lok Carabiner
Omega Pacific 1/2" Steel Modified D NFPA Screw-Lok
DMM Revolver Screwgate
$16 - $18
Petzl William Ball-Lock