TMD Locks, a company based in Almere, the Netherlands, initially specialized in securing automated ticket dispensers before branching out into bicycle security. This summer, the company introduced the TMD Chain Lock, a high-tech anti-theft device designed to be more convenient and less bulky than traditional bike locks. The lock features keyless unlocking via Bluetooth, which automatically recognizes a user's smartphone when it is within range. Users can simply press a button on the lock to open it, even with their phone in a pocket, eliminating the need to open an app for each ride. The TMD Chain Lock comes with a mobile app that offers additional features, such as sharing access with up to five people, tracking the last parking location of the bike, and monitoring the lock’s battery level. In case of a smartphone battery failure, the lock can still be opened using a physical button and an emergency code. The lock also includes a 100 dB alarm that activates if the bike is moved while parked. This alarm can be triggered either through the app or by pressing the lock’s button twice. The chain is constructed from manganese tempered steel, wrapped in a protective sheath made of Kevlar and Dyneema, materials known for their strength and resistance to cutting and fire. This design allows the chain to be thinner than average without compromising security. The lock is available in three sizes—70 cm, 110 cm, and 160 cm—with weights of 1.3 kg, 1.7 kg, and 2.1 kg, respectively. It is certified under ART-2, a Dutch security standard used by insurers to validate bike locks. The lock has an IP57 rating, meaning it is protected against dust and water, and its battery lasts up to nine months, fully recharging in two hours. The product comes with a two-year warranty and is available in navy blue, beige, and black. The TMD Chain Lock is priced starting at 229 euros for the 70 cm model, with the 110 cm version costing up to 286 euros. While the lock offers advanced features like keyless access, an alarm, and a high security rating, its price is significantly higher than standard ART-2 certified locks. This premium pricing reflects the added technology and materials used in its construction, though it may still be considered steep for some cyclists.