It took me a while to become convinced of the value of retzuous that were black on both sides. At first I thought it was a gimick. After a while I changed my mind for two reasons. Firstly I researched the halacha. I saw that the Rambam considers it a good thing if the back of the retzuzous are the same color as the battim. The Ohr Zeruah sides with this Rambam, as well as the Beis Yosef, the Darchei Moshe, and the Lishkas HaSofer (Reb Shlomo Gansfried). Secondly, I saw that many people who have regular retzuous are wearing posul tefillin. My Ultra Double Black Retzuou are dyed before they are painted so that even if some of the paint comes off, they will still be completly black. Take a look at the picture below. I purposely sanded the retzuah in such a way that had it not been an Ultra Double Black Retzuah it would have become posel, just like in my post entitled, Posel Retzuous. As you can see they are still black, and completly kosher. The price for a set (shel yad & shel ros) is between $85 and $125 depending on which quality leather is used. These retzuous come with a letter certifying their kashrus. I can put on new retzuous while you wait, so if you are passing through Monsey, and you would like to have me evaluate your current retzuous, give me a call at 845-290-2546. Or if I am doing a Mezuzah House Call in your neighborhood, I can take a look while I’m working on your mezuzos.