Master Lock
Master Lock Griptight Circuit Breaker Lockout Set (491B + 493B) 506
Model 506
Best price
Lowest we’ve seenWhere to buy
| Retailer | Price | Availability | Visit |
|---|---|---|---|
| Cheapestchecked 23 hours ago | £16.94 | In stock | Visit Blueperry agriculture (UK) (opens in a new tab) |
 checked within the hour | £19.95£23.54 | In stock | Visit Tooled Up (opens in a new tab) |
 retailer's price from 16 Jul 2026 | £20.15 | In stock | Visit Blueperry Tool & Builders Merchants (UK) (opens in a new tab) |
Prices exclude delivery. We may earn a commission if you buy through these links, which never affects the ranking above — it is always cheapest first.
Price history
Full price historyThis is the lowest price we have recorded. If you were waiting for a drop, this is it.
About this product
This lockout set allows electricians and maintenance engineers to safely isolate circuit breakers during servicing, preventing accidental re-energisation. It comprises two devices: the MLK491B, suitable for wide and tall breaker toggles, and the MLK493B, designed for standard breaker toggles, giving compatibility across various switchgear installations. Both devices are built from hardened steel with a powder-coated finish and reinforced polymer components, intended to withstand harsh industrial environments. Their narrow profile allows multiple lockout devices to be fitted side-by-side on adjacent breakers, suiting densely populated distribution boards and consumer units, while the mounting system is designed to be secure and simple to fit for reliable lockout.
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