Nickel plated-brass Rock Slides are a great combination of tone and string feel. They are slippery like glass, but have the weight and long sustain of brass. Unlike the polished brass slides, they remain slippery for a very long time.
Small - 17.5mm x 47.5mm - Ring Size 6-8
Medium - 19.5mm x 58mm - Ring Size 8-10.5
Large - 21.5mm x 59mm - Ring Size 10-12