TCS KAM4P-MH, HO Scale Motor Decoder:
A full featured, 4 function, 3.5" (88.9mm) harnessed decoder with a built in Keep-Alive™. The built-in Keep-Alive™ will keep your locomotive operating for 6-15 seconds without power (dirty track, bad contact, etc. etc.). Included is our auto-adjusting BEMF for outstanding slow speed performance. Also includes Quiet Drive for super quiet engine performance.
 
MSRP is $79.95. (Picture courtesy of TCS.)