Rimless Ultra Clear Tanks by Ultum Nature Systems These rimless aquariums are carefully crafted using 91% clarity Diamant glass, a highly transparent extra clear glass with very little residual green color. The low iron content in the glass provides uninterrupted crystal clear visibility. The 45° mitered edges are bonded together using high-performance German silicone specifically designed for aquarium construction. Each Ultra Clear Tank comes with a black leveling mat. Why UNS Rimless tanks? 45° Mitered Edges 91% Clarity with Diamant Glass High-Quality German Silicon Free Black Leveling Mat. Size Chart Guide Model Size Glass Thickness (mm) Volume (Gal) 45L 17.71 x 6.7 x 6.7 in 45 x 17 x 17 cm 5 3.6 60 L 23.62 x 7.87 x 7.87 in 60 x 20 x 20 cm 5 6 90 B 35.43 x 7.87 x 9.84 in 90 x 20 x 25 cm6 12 90 L 35.43 x 11.81 x 11.81 in 90 x 30 x 30 cm 8 21.4