- Alternate action call button to place or cancel a call- Intelligent call progress detection for automatic hang-up on CPC, silence, busy signal, or time out- Telephone line powered- Weather resistant features: mylar speaker, gaskets, internally sealed push button switch, UV stable exterior, enamel coated PCB- Optional Enhanced Weather Protection (EWP) available for greater weather resistance- Adjustable microphone and speaker volume- Programmable maximum call length- Selectable auto-answer feature allows r