QSL-1/4-10 Elbow Connector, R 1/4 Male, Push In 10 mm. The Quick Star QSL range offer a convenient push-in fitting system for compressed air and water with over 1000+ types of standard and function fittings. These high quality, male or female threaded to tube adapters offer a variety of Metric, G parallel or R tapered threads and diameters to suit each and every connection.