1 1/2" knife gate drain valve

This knife gate drain valve is designed for emptying waste tanks. So is it quick at draining? On one side it has a 38 mm (1 1/2") diameter threaded nipple and a screw-on cap; on the other side there is a glue-on nipple.
It is equipped with a short pull tab.

Dimensions (WxHxD): 8.1 x 22.5 x 10.5 mm.
Diameter: 38 mm/ 1 1/2 ".
Weight: 280 g

An adaptor is available as an option for connecting the valve to the tank.