Guild heal kits

Sorry if stupid question but I don't really get the guild heal kits requests. When I send heal kits to guild members, I would have assumed that my total personal number of heal kits reduces but it doesn't seem to be the case. Is someone able to shed light on how this works for me please.

Thanks
When you send heal kits to them theirs increases, likewise when they send you kits, yours increases. your not sharing, your getting new kits mate
I think I understand, but what is the catch? What are you giving up or loosing in return for sending heal kits, if anything at all. If the answer is nothing then why aren't people constantly sending heal kits then...or are they?
You lose nothing, and it all comes down to how active people are im normally at over 1000 sent a season
Its one of the major rewards of being in a guild, along with the guild challenges, strategy sharing and general banter, all rewards are generated from thin air