Here are some links that may help -- look at the Amazon links, even if you buy locally, so you can be sure to get the right thing! Watch the Teflon tape video -- most people use it incorrectly.
Poolmaster 36670 Standard 1/4-Inch Threaded Side Mount Pressure Gauge @ Amazon
Oatey 31403 Yellow GAS/TFE Tape, Dispenser Pack, 1/2-Inch x 260-Inch @ Amazon
How to use teflon tape on pipe threads on YouTube