XVL Pull-out Spray Head for Bathroom Kitchen Faucet Replacement Part, Chrome T6501b Please consult the manufacturer of the faucet whether the connector of is G1/2 (About 2 cm or 0.8 inch) to avoid the mistake about the size.And please check the image of the size and make sure this is the right size (small or big) you expected. Connector G1/2(About 2 cm or 0.8 inch), Not universal ,Not NPT. Please check the image of the dimension about this product.Thickness of the screw threads about the hose needed to install with this head is less than 0.4inch.Please Check the dimention. The default working funtion is stream(the first funtion). You can use the switch to transform stream to dispersed water(the second funtion). The round button is only for making water pause and you should keep pressing this button to hold water off.Once you turn the water off or stop pressing the round button,it reverts back to the default working funtion(the first funtion).