Comparison : Item # 774HLSS6MM, St.St. 316 Bulkhead Union, One-Lok® Tube Fitting 6mm x 6mm
Item # 774HLSS8MM, St.St. 316 Bulkhead Union, One-Lok® Tube Fitting 8mm x 8mm
Item # 774HLSS10MM, St.St. 316 Bulkhead Union, One-Lok® Tube Fitting 10mm x 10mm
Item # 774HLSS12MM, St.St. 316 Bulkhead Union, One-Lok® Tube Fitting 12mm x 12mm
Item # 774HLSS14MM, St.St. 316 Bulkhead Union, One-Lok® Tube Fitting 14mm x 14mm