HASMX 647956-00, 64795600 Trigger Valve Assembly for Dewalt Fits the following models: D51256 Type 1 Finish Nailer Kit, D51256 Type 2 Finish Nailer Kit, D51238 Type 1 Brad Nailer Kit, D51430 Type 1 - Amazon.com
DEWALT 16-Gauge Pneumatic 1 in. - 2-1/2 in. Nailer D51257K - The Home Depot