This is HOT selling one with beautiful design .

Features :

*Wide measuring range:Measuring range of standard cylinder lens can reach up to 6D with the revolution 0.25D.In the range of 20 ,accuracy will be lower than 0.5 ,using the rotary prism with trimming gear.
*Synchronal cross cylinder:Rotating of the cross cylinder is synchronal with the adjustment of the cylinder axis.If you change the axis,the cross cylinder will adjust to the appropriate position synchronously,it is highly-efficient.
*Convenient operation,clear scale:With the special design,you can switch to the appropriate lens quickly.Because of oxidation treatment,all the scale and symbols are persistently clear.
*Multifunctional adjustment:P.D. can be adjusted from 48mm to 75mm,quick switch between near P.D. and far P.D.,between near visial angle and far visual angle.You can ajust the binocular horizon and the distance between the vertex of the cornea and the instrument.
*Multifunctional auxiliary lens:The complete set of SIGM VT-1 multifunctional auxiliary lens includes the following:Red-Green lens,polarizer,prism,stenopeic lens,etc.You can switch quickly between anyone of them.
*Fast and accurate conclusion:There are two spherical lens turntables with 0.25D and 3D diopter steps.Measuring range:+16.75D~0~-19D.You can adjust it much more accurately if you use the 0.12 auxiliary lens.

Specification 

Item and range of measurement:
Myopia:		0 to -19.00 diopter in 0.25 diopter step (0.12 diopter step)
Hyperopia:		0 to +16.75 diopter in 0.25 diopter step (0.12 diopter)
Astigmatism:		0 to -6.00 diopter(-8.00 diopter) in 0.25 diopter step
Phoria and vergency:		20 to 0 to 20 by 1 step;Inner 40;Outer
Near vision test:		Main optical axes of both lenses converges by means of a tilt mechanism at 40cm in front of the eyes at 64mm P.D. If P.D. for far vision is less then 54mm,converging operation stops.
Binocular balance test:		Rotary prism and polarizing lens methods are
P.D :		48 to 75mm by 1mm step
Level adjustment:		More than 4.5 for right and left banks
Dimensions:		335(at 64mm P.D. setting) 97 294mm
Auxiliary lens:
O.Q:	Open aperture
R:	Retinoscopic lens;+1.50 diopter spherical lens(for 67cm)
P:	Polarizing filter.Used for polarizing testing of phoriz,Binocular balance of stereoscopic vision.
RMV:	Red Maddox rod is set vertically.
WMV:	White Maddox rod is set vertically.
WMH:	White Maddox rod is set horizontally.
RL:	Red lens.
GL:	Green lens.
PH:	A 1mm diameter pinhole is provided.This lens is used to determine if Poor vision is due to refractive abnormality or other caused.
6 U:	6 diopter base up prism.Used for the tests such as horizontal phoria test.
10 I:	10 diopter base in prism.Used for the tests such as vertical phoria test.