The Parks Medical Electronics Model 811-B Ultrasonic Doppler Flow Detector is a reliable, non-directional Doppler device widely used in medical and veterinary settings for vascular assessments and blood pressure measurements. 

Key Features:

• High-Frequency Probe: Equipped with an 8.2 MHz probe, ideal for detecting blood flow in peripheral vessels and measuring systolic pressures where traditional stethoscopes may be ineffective. 
• Built-in Speaker: Allows for immediate audio feedback during assessments. 
• Rechargeable Battery: Ensures continuous operation without frequent battery replacements.
• Auxiliary Headphone Output: Provides an option for private listening or recording of Doppler signals. 

Applications:

• Vascular Studies: Assists in detecting blood flow and measuring systolic pressures at sites where a stethoscope cannot be used, as well as pulses that are too faint for a stethoscope to detect reliably. 
• Intraoperative Monitoring: Enables real-time blood flow monitoring during surgical procedures. 
• Veterinary Medicine: Utilized for continuous pulse monitoring and hypertension screening in animals of all sizes. 

Specifications:

• Dimensions: 8 inches (height) x 5.5 inches (width) x 3 inches (depth), including handle. 
• Weight: Approximately 2.87 lbs (1.34 kg) with battery. 
• Frequency: Factory tuned to 8.2 MHz; compatible with various probe styles (pencil, infant flat, adult flat, skinny pencil).