The Simpson Strong-Tie® GWL lathing washer is designed for use with both the G3 gas-actuated fastening tool and the GCN-MEPMAGKT gas-actuated concrete nailer tool to attach lath to the wall surface for overlaying scratch coats, brown coats and stucco. These washers are held onto the single-shot nosepiece of either the G3 with the G-422 magnetic ring or the GCN-MEPMAGKT with the GMR-2 magnetic ring. The washers attach to concrete or CMU substrate with gas-driven pins (GDP), which fasten through the washer.