Comenzar-US via Amazon offers the Comenzar Dental Guard 4-Pack for $10.39. Coupon code "UQL4O6SI" drops it to $6.23. Plus, Prime members bag free shipping. That's $4 off and the lowest price we could find. (For further comparison, we saw a 2-pack for this price three weeks ago.) Users can cut these silicone mouthpieces to fit. Deal ends August 31.