Model 4722 "Lens" 

Serial: A05010143 - A05010141

Specifications

Enclosure / Bass-reflex (12mm thick MDF)
Driver / 10cm full-range unit
Impedance / 4 ohms
Efficiency / 85dB 1W/m
Maximum Input / 25W continuous (40W peak)
Dimensions / 160mm (w) x 195mm (d) x 260mm (h)

The proprietaly 10cm Full-range driver unit
designed by Takanori Ohmura

Cone material is the coated Amid-Fibercloth cone that realizes higher rigidity and less storage of energy compared to simple amid-fibercloth cone.

Edge is made by a new material developed after 5 years of experimentaion. It is extremely light and flexible with an ideal damping character against the cone.

New "Low-Q-Damper" to control the voice-coil accurately.