1. Select the product of the enterprise with high visibility, stable quality and good after-sales service.
2. Observe the product appearance quality situation, including lock, lock body, lock tongue, hold hand and cover parts and related accessory is complete, plating parts, spray painting piece surface luster is bright, uniform, there is no rust, oxidation signs and breakage.
3. Check the product packaging of the logo, whether a complete logo (including product implementation standards, grades, production enterprise name, address, production date), the packaging is firmly, the contents of the specification and product compatibility.
4. Check the use of the product is reliable, flexible, should choose two more products to carry out a control check, especially the purchase of two-way lock products, must use all the key to the internal and external lock test switches. should also inspect the product insurance agency situation, suggest each lock at least three times above.
5. Check the key Ervatamia divaricata situation, such as five key teeth, each key should not be less than three different key teeth, while the first and fifth teeth should try not to choose the deepest key teeth, conducive to the key plug and easy to break.