X-Chock works as advertised but CANNOT be used as a chock replacement. The BAL contains a notice that its use when raising a trailer or raising/lowering a jack WILL VOID the warranty. They can only be used AFTER the trailer has been leveled and MUST BE REMOVED before preparing to hitch. So you still need wheel chocks to secure the trailer for other uses. This was not clearly stated in the description. You will only find it if you read the reviews or the Q&A (must expand to read all answers). However, they fix the pendant securely. My tires are closer together so I have to remove the X-chocks one at a time to place chocks under the tires to raise or lower the jack. Tire pads are too low in my application. Would buy again.