Amazon.com : M MINGLE Garden Hose Adapter, Male to Male, Female to Female, 3/4 Inch Brass Connector, 4-Pack with Extra 4 Washers : Patio, Lawn & Garden
Straight female hose adapter 1/2" x 13 mm
B&K 3/4-in x 3/4-in Threaded Female Hose x Female Hose Adapter Fitting in the Brass Fittings department at Lowes.com
Melnor Metal Double Female Adapter 59Z FB-HD
GRAINGER APPROVED Garden Hose Adapter, Fitting Material Brass x Brass, Fitting Size 3/4 in x 1/2 in - 20XP99|707420-1208 - Grainger