Use the Monoprice promo code that is listed here to get a 20% discount off select products. The offer is only valid through September 29, 2018. Certain items and gift cards are excluded when redeeming Monoprice promo codes. Your order total must be between $150 and $5000 to qualify. The promo code for Monoprice will not work if you have not added a sufficient amount of eligible merchandise to your shopping cart. You may not combine the discount with any other promo codes for Monoprice. Furthermore, the offer does not stack with other promotions or preferred pricing discounts. Only one Monoprice promo code may be redeemed per cart and there is a limit of two redemptions per customer.