BLOCK STEM is a P3 Thatcham approved anti-theft device for Tractors, Excavators/Mini Diggers and Earth Movers, made from C4 steel with hardener, which is applied to the steering ram on full lock. So how does it work? Block Stem fits closely over the steering ram on any power assisted vehicle. It is fitted with the steering on full lock, thus preventing the vehicle being moved except in a circle, even if the engine is started by the thieves.It has been proven to be not only a visual deterrent, but also a very effective immobiliser. We are Endorsed by JCB / John Deere / Armatrac / MultioneUK. Please not the one photo shows two - block stems they are for illustration only showing what two look like if needed this sale is for one only! The item "Manitou Telehandler Unbeatable Anti Theft Device for Tractors Approved by JCB" is in sale since Friday, November 23, 2018. This item is in the category "Business, Office & Industrial\Agriculture/Farming\Tractors\Modern Tractors". The seller is "2005jireh" and is located in Kingswinford. This item can be shipped worldwide.