Ring Stretcher in wooden box For the partially sighted_No - this Presidium "Digital refractometer"

- this Presidium "Digital refractometer" does measure refractive index but

Backlit display can be set to turn on (good in bad light) or to stay off (good for battery-saving) or to stay on for 15 seconds each time you weight an item or press a button

use this instead of a diamond tester because Cubic Zirconia

For coloured stones only

Ring Stretcher in wooden box For the partially sighted_No - this Presidium "Digital refractometer"Special clearance price while stocks last (once sold, there are no more) Handheld ring stretcher. Works by 'squashing' the ring around the outside as you turn handle. Includes 16 steel discs for ring shanks with thicknesses of between 4mm and 1mm. Yes it works fine but it's hard work compared with the large bench workshop models . However, as a low cost, simple, effective ring sizing machine go for it!