Tip - Almost all underground electric gate motors require adequate drainage or a soak away, although the Sub 180 is a fully sealed unit, also the Sub Motor is oil immersed for long life. There is also the R21/351/SUB which is a submersive sealed unit.
Our favourite, Roger Technology Underground BR21/362 Gate Kit, it has proved to be the most reliable. The on board encoder ensures excellent obstacle detection. The Brushless magnet motors are noiseless, generate no heat or friction and have a non-stop running ability. To top it off they have solid state switches instead of relays for the ultimate in relibility, and if that isn't enough they have a second bearing and can carry up to a ton in weight, and come pre wired with 10m of cable on each motor. For the cherry on the cake, add battery back up.