Unable to find any PTR-records for the specified domain/ip :(
Log
+000
Resolving PTR record of '15.158.109.0'
+350
ERRNo PTR record availible DNS server 'pdns1.ultradns.net' raised an NotExistentDomain error, while beeing queried for PTR-records on domain '0.109.158.15.in-addr.arpa'.