Good for Custom designer faucet with no aerator.
Two inlet connections (one hot and one cold) will require 2 adapters. The max output of the faucet will be the sum of your hot and cold flow rate combined.

Pressure Compensating 1/2” NPT Male x 1/2” NPSM Female -

Supply line adapter fixes those tough retrofitting issues. The 1⁄2” adapter should be placed directly under the counter between the faucet and the supply line making it invisible (harder to reach and see).
The single knob or two handle faucet generally have 1/2" pipe connections.

NEOPERL water saver can reduce consumption, faucet water savers deliver a constant flow rate almost regardless of the flow pressure. These will work for facuets without aerators, rectangular faucets and hard to replace flow rates.

Choose from:
0.25 gpm - Black flow regulator
0.5 gpm - Lime green flow regulator
0.6 gpm - Beige flow regulator
0.75 gpm - Red flow regulator
0.9 gpm - Olive green flow regulator
1.0 gpm - Blue flow regulator

• Solid brass construction. Chrome Plated.
• Can be easily installed under the sink between the supply line and the faucet.
• Ideal for faucets where the aerator cannot be replaced but a lower flow rate is desired.