Arrow T50 Series top quality 0.050 wire staples to suit:
T50, T55, T50PBN, HT50P (up to 12mm only), HTX50, ETFX50, ETF50PBN, CT50K, 5700 AND 8000.

The Arrow ARRT50916S T50 Staples Box contains top quality 0.050 wire staples for use with T50 and T55 tackers:

These staples can be used for heavy insulation, metal lath, cornerite, roofing, etc. with the following specifications:
Size: 9/16 inch / 14mm
Qty: 1250 staples