How can you make a Dev Product award health, speed, or a gear?

Well I want a dev product to give health and speed and to be able to stack. I do not want the health to be restored but to just add to there maximum health. And when they die they lose the speed or health whatever they bought forever until they buy more. My recent problem with it is that you lose it on death but when you rejoin the game you get all the speed you paid for and i don't want that with the gear or health and neither the speed I want them all to be gone from the people forever until they buy more. Hope you guys can help! :D

If you got a reply tell me the script or maybe a link. :P If you know just one of those scripts to just add speed let me know you don't have to give me all three of them .! Thank you for reading!

1. Please place your script you have for your Dev Product as you seem like you have the issue of dev products being regained again
2. This isn't a requesting site