Replacement control assembly — the electronics module mounted in the reel hub that drives the water-contact detection, sensitivity adjustment, and the audible and visual alerts.

Two versions, matched to tape length:

• ET (up to 300 ft) — for 100–300 ft / 30–100 m meters.
• ETL (500 ft and longer) — for 500 ft and deeper. Longer tape means more line resistance, so the control assembly differs. When ordering this version, tell us your tape length.

Order the version matching your meter. If the unit powers up but won't trigger reliably, try a fresh 9-volt battery and check the probe first — a control assembly is rarely the actual fault.

See also the buzzer and battery holder, and the probe assembly.

Browse all Geotech WLM parts & accessories, or contact us — we can often diagnose it over the phone before you buy a part.