diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 0000000000000000000000000000000000000000..1b83d04eca61f95811ef00b6e6da34da4937807b
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,19 @@
+# Contributing
+
+If you have any issues or ideas for improvement you can send me an email to _thl-cmk[at]outlook[dot]com_.
+
+For some fixes/improvements I migth need a _snmpwalk_ fom the device in question.
+This must contain
+
+- .1.3.6.1.2.1.1.1 sysDescr 
+- .1.3.6.1.2.1.1.2 sysObjectID
+
+and all the SNMP OIDs used in the plugin.
+
+If you run the _snmpwalk_ command, please uses these options _**-ObentU**_ in addition to your snmp options like community, version etc.
+For example:
+```
+snmpwalk -v2c -c public -ObentU 10.10.10.10 .1.3.6.1.2.1.1.1 > hostname.snmpwalk
+snmpwalk -v2c -c public -ObentU 10.10.10.10 .1.3.6.1.2.1.1.2 >> hostname.snmpwalk
+snmpwalk -v2c -c public -ObentU 10.10.10.10 .1.3.6.1.4.1.2620.1.6 >> hostname.snmpwalk
+```
diff --git a/README.md b/README.md
index 8f1f44fd694dcb6b3f4c73f02c5de1afba678dce..9e23f506595b982f437bdc1f5cb265f56876d245 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-# inventory of Check Point Hardware Appliances
+# inventory of Check Point Hardware Appliances [(Download the MKP package)](/../../../-/raw/master/inv_checkpoint_base.mkp "Download MKP package")
 
 **Note: this package is for CheckMK version 2.x. For other versions see the corresponding branch.**
 
@@ -8,5 +8,10 @@ adds the following to the inventory:
 * Deployment agent version, SVN version, OS name, version and build
 * Hostlabel "checkpoint/device_type:maestro" if its find a Check Point Maestro SMO system
 
+---
+#### Want to contribute?
+Nice ;-) Have a look at the [contribution guidelines](CONTRIBUTING.md "Contributing")
+---
+
 Here is a sample inventory
 ![sample Check point inventory](/doc/sample.png?raw=true "sample Check Point inventory")
diff --git a/agent_based/inv_checkpoint_base.py b/agent_based/inv_checkpoint_base.py
index 53215a7c36a5be6120a9072d1d7f7ebac33af68f..ceda8dab384bbb69a6f7f18eea917783a39a88f2 100644
--- a/agent_based/inv_checkpoint_base.py
+++ b/agent_based/inv_checkpoint_base.py
@@ -29,12 +29,12 @@
 
 from typing import List, NamedTuple
 
-from .agent_based_api.v1.type_defs import (
+from cmk.base.plugins.agent_based.agent_based_api.v1.type_defs import (
     HostLabelGenerator,
     StringTable,
     InventoryResult,
 )
-from .agent_based_api.v1 import (
+from cmk.base.plugins.agent_based.agent_based_api.v1 import (
     Attributes,
     HostLabel,
     register,
@@ -95,7 +95,7 @@ def parse_inv_checkpoint_base(string_table: List[StringTable]) -> List:
 def host_label_inv_checkpoint_base(section: List) -> HostLabelGenerator:
     for invPath, key, value in section:
         if key == 'appliance_series' and value.lower() == 'maestro':
-            yield HostLabel('checkpoint/device_type', 'maestro')
+            yield HostLabel('checkpoint/device_type', 'maestro_security_group')
 
 
 def inventory_checkpoint_base(section: List) -> InventoryResult:
diff --git a/inv_checkpoint_base.mkp b/inv_checkpoint_base.mkp
index e57b660a64ad5e96e37d8730915c1b97b205d479..e31aaddcfce0c4bf175ef0d8df63837a49777426 100644
Binary files a/inv_checkpoint_base.mkp and b/inv_checkpoint_base.mkp differ
diff --git a/packages/inv_checkpoint_base b/packages/inv_checkpoint_base
index b357c7a0ced8322bace27397f854f8c6d4bc28d8..947af7b32d5be285846c8cbda5c1603806b59d34 100644
--- a/packages/inv_checkpoint_base
+++ b/packages/inv_checkpoint_base
@@ -13,5 +13,5 @@
  'title': 'Check Point appliance base inventory plugin',
  'version': '20210318.v.0.1a',
  'version.min_required': '2.0.0b8',
- 'version.packaged': '2.0.0p1',
+ 'version.packaged': '2021.07.14',
  'version.usable_until': None}
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