At the moment Monoprice offers 15% off all orders when you use the coupon code at checkout with promo code TREATS at checkout at monoprice.com
How to use monoprice.com coupons :
1 – Copy the coupon/ promotion / discount code TREATS.
2 – Go to website monoprice.com and remember to paste the code copied to the coupon/discount/promotion box at check out page
3 – Wait for the discount and Enjoy your order