It would also be good to know what has happened to it and why.
Umarex offer a 12 month warranty to their business customers:
"All claims of the customer based on defects become statute-barred twelve (12) months after delivery of the Goods. This period does not apply if we acted with intent or gross negligence or in the case of liability for injury to life, health or body. Furthermore, it does not apply if we are liable under a guarantee or in the event of intentional deceit on our part. § 445 b of the German Civil Code shall also remain unaffected."