You are buying 4 caps !
These easy to install  replacement valve caps constantly monitor your tire pressures with clear , bright color indicators . 
GREEN, RED, visible through upper transparent portion of indicator. 

GREEN : CORRECT TYRE PRESSURE 
GREEN / Half RED : AIR LOSS 20% PSI, INFLATE TYRE TO RECOMMEND AIR PRESSURE. 
RED :  AIR LOSS 25%~30% PSI, INFLATE TYRE IMMEDIATELY, 
DO NOT OPERATE VEHICLE UNTILPROBLEM TYRE IS INFLATED TO RECOMMENDED AIR  PRESSURE.

Gozens valve caps are precisely made for a full range of cars , vans , motorcycles and light trucks and are accurate to within 1 lb .

Utilize the Gozens safety pressure indicators and travel with confidence .   
Material: Brass Body
100% Made in Taiwan 

Be sure to choose the Gozens to match the front and rear pressure as recommended  by the vehicle manufacturer.

New in Packaging (Not Retailing Box)
Condition: 100% Brand New, never been installed

PLEASE SPECIFY WHICH PRESSURE (Psi) YOU WANT WHEN ORDERING :90 Psi, 100 Psi, 110 Psi, 120 Psi

• Easy to install 
• Increased safety 
• Increased gas mileage
• Increased tire life
• No need any power supply/ battery etc.

Easy to install Gozens