Surftest "SJ-210/SJ-310" and "SJ-410" detectors are not compatible.
Example) The detector of the Surftest SJ-210 can be mounted on the drive portion of the SJ-310, but not into the drive unit of the SJ-410
Example) The detector of the Surftest SJ-310 can be mounted on the drive portion of the SJ-210, but the SJ-410 but not into the drive unit of the SJ-410
Example) Surftest SJ-410 detectors cannot be installed into the drive unit of the SJ-210 or the SJ-310.