The Plas-Labs Feret restrainer is a modifed version of a similar device initailly described by Dr. Daniel McLain in the Volume #35, No. 7 issue of Lab Animal magazine. 
 
The Plas-Labs units are offered in four (4) sizes taking into consideration the animals age, weight and sex. The units are constructed of optical quality clear acrylic (Perspex™), and a formed black plastic nose cone with an Acetal™ locking slide. The main restraining cylinder can be rotated 360° to provide complete access to the animal. All units are mounted on a white acrylic base plate with suction cup feet to guarantee reliable stabilty during testing procedures. Counter top space required is 11.5" x 21."