Thumb Score: +20

Dozyant via Amazon [amazon.com] has 2-Pack Dozyant Propane Tank Gauge Level Indicator & Leak Detector (5-40 lb) on sale for $12.99. Shipping is free w/ Prime or on orders $35+.

Product Description from Store:[LIST][*]Dimensions (each): 4″ x 2.5″ x 2″[*]2-pack[*]Model: TXD2388[*]Compatible with QCC1/Type 1 connections and 5-40 lb propane tanks[*]Monitors fuel level without removing the tank