STOCKHOLDERS' EQUITY - Stock options (Details) - $ / shares	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Options Outstanding, Exercise Price	$ 0.66
Options Outstanding, Number of Options	590,000	370,000
Options Exercisable, Weighted Average Remaining Life	2 years 3 months 18 days
Options Exercisable Number of Options	324,167
0.66 Exercise Price
Options Outstanding, Exercise Price	$ 0.66
Options Outstanding, Number of Options	370,000
Options Exercisable, Weighted Average Remaining Life	2 years 3 months 18 days
Options Exercisable Number of Options	324,167
1.99 Exercise Price
Options Outstanding, Exercise Price	$ 1.99
Options Outstanding, Number of Options	10,000
2.03 Exercise Price
Options Outstanding, Exercise Price	$ 2.03
Options Outstanding, Number of Options	20,000
2.05 exercise price
Options Outstanding, Exercise Price	$ 2.05
Options Outstanding, Number of Options	10,000
2.08 Exercise Price
Options Outstanding, Exercise Price	$ 2.08
Options Outstanding, Number of Options	10,000
2.13 Exercise Price
Options Outstanding, Exercise Price	$ 2.13
Options Outstanding, Number of Options	20,000
2.27 Exercise Price
Options Outstanding, Exercise Price	$ 2.27
Options Outstanding, Number of Options	30,000
2.43 Exercise Price
Options Outstanding, Exercise Price	$ 2.43
Options Outstanding, Number of Options	20,000
2.44 Exercise Price
Options Outstanding, Exercise Price	$ 2.44
Options Outstanding, Number of Options	100,000