Its properties are much better than the multi-order waveplate because of its thinner thickness (less than 0.5mm). Better temperature (38°C), wavelength (1.5nm) and incident angle (4.5°) bandwidth and high damage threshold make it widely used in common application. Also, it is economical.               

Specifications:                 

Material: Crystal Quartz          
Dimension Tolerance: +0.0, -0.2 mm           
Wavefront Distortion: < λ/8 @ 632.8 nm            
Retardation: λ/8, λ/4, λ/2, or λ (typical)        
Retardation Tolerance: < λ/500 (typical)       
Thickness: 0.2~0.4mm (determined by retardation)     
Wavelength Range: 240-2100 nm             
Parallelism: <1 arc second          
Surface Quality: 20-10 scratch and dig                

AR/AR Coating R<0.2% per face is available upon request.             
Other retardations are also available.