Unable to find any PTR-records for the specified domain/ip :(
Log
+000
Resolving PTR record of '15.220.0.0'
+112
ERRNo PTR record availible DNS server 'ns1-16-multi.ec2-rdns.amazonaws.com' raised an NotExistentDomain error, while beeing queried for PTR-records on domain '0.0.220.15.in-addr.arpa'.