2. Fair Value of Financial Instruments

We follow a three-level fair value hierarchy that prioritizes the inputs to measure fair value. This hierarchy requires entities to maximize the use of “observable inputs” and minimize the use of “unobservable inputs.” The three levels of inputs used to measure fair value are as follows:

Level 1: Quoted prices (unadjusted) for identical assets or liabilities in active markets as of the measurement date.

Level 2: Significant other observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data.

Level 3: Significant unobservable inputs that reflect assumptions that market participants would use in pricing an asset or liability.

At June 30, 2018 and 2017, all of our cash, trade accounts receivable and trade accounts payable were short term in nature, and their carrying amounts approximate fair value.