16 Gram Whipped Cream Charger Hybrid

I am making my first hybrid rocket using a 16 gram whipped cream charger and I need to know the dimensions of the 16 gram charger. Also, does anyone have any good design recommendations for the injection part of the motor? All help with this will be greatly appreciated as this is my first time making a hybrid rocket.

Thank you,
Jwell

I got a microhybrid from Leland Dexter a few years ago, I've been too busy to do anything with it but it's on my list. You can get the cartridges from eBay/Amazon. I got one out of the box, it's about 21mm dia x 85mm long (counting the shoulder, which is about 8.5mm dia x 10mm long). Leland sold a rocket especially for these, it used 30mm Quest tubing and a plastic fin can. My plan is to put a Quark and an Eggfinder Mini in it... when I get it done.