Model CHL 621-4 is four rotary valve F Helicon of V. F. Cerveny brand.
Traditional construction proven by many years and long-time experiences of the instrument makers provide a really nice timbre in all range.

Specification:  

•  Key: F
•  Bore: 18.2 mm (.717″)
•  Bell: 420 mm (16.54″) hand shaped, wire reinforced.
•  Body: yellow brass
•  Mouthpipe: nickel-silver
•  Valves : 4 rotary valves, nickel silver spatulas, nickel silver valve casing, valves are being manufactured by CNC lathe.
•  Trimmings: Nickel-silver hand lapped inner and outer tuning slides, nickel-silver stays.
•  Feature: Adjustable finger ring, tuning slide waterkey, minibal action, hand engraved valve caps and levers, lightweight construction.
•  Finish: High gloss polished and lacquered, different custom finishes available on request.
•  Outfit: silver-plated mouthpiece,and cover