If I can give less than one star I will do that for sure, I made my order in January and waited for almost 3 months to receive my loups... and guess what when I received it, I was very disappointed with them ... there is issues with the working distance, it hurts my eyes and starting have a lot of eye pains because of the eye strain... also the magnification is not real!!! I chose the 3.3 magnification power and in reality it look like there is no magnification at all!!!! So I wasted 4 months till now and my eyes start hurting me and till now I didn't have the chance to start practicing dentistry with my loups because of all of the issues..