Product Codes : 56-A419.55 / 56-A419.40 The MHS 500 is an open faced Motorcycle Helmet headset to be used in conjunction with Midland, Alan and Albrecht Two Way Radios. The MHS 500 is compatible with all our radios apart from the Midland 777 which is a single pin connection method. The unit itself comes in two parts the top part is the speaker/headset system, this connects to the PTT (push to talk system) which can be handle bar mounting. Please note when using the MHS 500 this unit is suitable as a PTT system only and not for VOX (voice activation) this is down to the fact the MHS 500 does not have ANC (active noise cancelling) and is a bare bones easy to use PTT system to enable Bike to Bike communication.