Redundant retention of a removable device

1. An apparatus comprising:

a first side comprising a first fastening portion and a second fastening portion;

at the first fastening portion, a first groove for receiving an elongated body and engaging a first retention mechanism, the first retention mechanism for attaching a removable device to a mountable device; and

at the second fastening portion, a second groove for receiving a circular body and engaging a second retention mechanism, the second retention mechanism attaching the removable device to the mountable device, independent of the first fastening portion.

2. The apparatus of claim 1 , the first side further comprising a body groove between the first fastening portion and the second fastening portion.

3. The apparatus of claim 2 , the body groove further comprising a decline face comprising a shallower end near the first fastening portion and a deeper end near the second fastening portion.

4. The apparatus of claim 3 , wherein the body groove receives an inclined face of the mountable device.

5. The apparatus of claim 1 , wherein the removable device may be removed from the mountable device only when both the first retention mechanism and the second retention mechanism are disengaged.

6. An apparatus comprising:

a mountable device comprising a first side having a first fastening portion and a second fastening portion;

at the first fastening portion, an elongated body having an inclined face parallel to and protruding from the first side and a flat face perpendicular to the first side;

at the second fastening portion, a circular body with a smooth circular face, the circular body protruding from the first side;

a removable device comprising a corresponding first side having a corresponding first fastening portion and a corresponding second fastening portion;

at the corresponding first fastening portion, a first groove for receiving the elongated body and engaging a first retention mechanism; and

at the corresponding second fastening portion, a second groove for receiving the circular body and engaging a second retention mechanism, independent of the first retention mechanism.

7. The apparatus of claim 6 , the first fastening portion further comprising a tab, wherein the tab is flexible to allow the first fastening portion to move away from the mountable device.

8. The apparatus of claim 6 , the mountable device further comprising four hooks, each hook of the four hooks located at a corner of the mountable device and protruding from a second side of the mountable device, wherein the hooks allow the mountable device to be attached to a pet collar using a retention structure for receiving the four hooks.

9. The apparatus of claim 6 , wherein the second fastening portion is flexible to allow the second fastening portion to bend allowing the circular body to disengage from the removable device.

10. The apparatus of claim 6 , the corresponding first side further comprising a body groove between the corresponding first fastening portion and the corresponding second fastening portion, the body groove comprising a decline face comprising a shallower end near the first fastening portion and a deeper end near the second fastening portion.

11. The apparatus of claim 6 , wherein the removable device may be removed from the mountable device only when both the first retention mechanism and the second retention mechanism are disengaged.