The L&R Mule Ear or Sideslapper percussion lock design allows the percussion nipple to be mounted directly into the barrel. Pull the hammer outboard to cock the lock. Unlike some mule ear locks this lock has both a half cock and full cock position on the tumbler. The lock plate is 5.1" long by 0.94" tall.
The tumbler is fitted with a fly detent to allow the use of set triggers. The mainspring is fitted with link between the mainspring and tumbler for smooth action.