Simplex

Simply put, this is the instrument offering digital technology with an easy-to-adjust configuration. No need for computers or software.
A 2-channel digital BTE, trimmer-adjustable instrument which provides excellent versatility.
A high fidelity programmable 2-channel BTE, trimmer-adjustable instrument which provides excellent versatility.
A high fidelity 2-channel, trimmer-adjustable instrument with an adaptive feedback canceller which reduces acoustic feedback (whistling).
source:audina