Lastly, a bit on pricing. Most practices will do about a three-time markup of the majority of their ophthalmic frames. Sunglasses will see 2.5 markup, on average or some come with MSRP pricing that you'll need to follow. I will note that when I said the majority of their ophthalmic frames have three-time markup, there is often times confusion about should I mark up the frames that are more expensive on the higher end of the spectrum and the answer is yes. Yes, you should. You should have a consistent markup on your most of your high-end products as well. Interestingly though, we don't hear that question regarding frames on the lower end of the spectrum and in that case, we recommend more than a three-time markup. So, for example, if you're purchasing frames for that cost you $20 and your markup of three times, there just isn't enough profitability to cover the other costs associated with that frame. So, on those real budget-type of frames, we recommend more than a three-time markup and we can discuss the pricing with you individually. So, on lenses, no real formula unfortunately, but also average is about a three-time markup on the base price of lenses. Some labs will have a suggested retail pricing sheet and others will work with you on your pricing. We do recommend that you phone shop your competition to have an understanding of what they charge for a sampling of their lenses.