sFlow packet capture size

[Saputra]

I want to ask something about the size of packet that sFlow capture, I send packet ping (ICMP) whose size is 98 Bytes, but when the sFlow capture that packet, the size become 110 Bytes, what does the addition of 12 bytes mean? I need help, Thank You very much.

I attached some picture, the first picture is the sFlow collector capture (i used sfdump), the Bpp (Bytes per packet size is 110 Bytes) and the second picture is the original packet ping size (which is 98 Bytes, captured by Wireshark)