These ultra-lightweight 6061-T6 aluminum canisters are threaded to be sealed with standard low profile water bottle caps.  (1.05" diameter, 1/4" high, 3 thread starts) 

Each weighs in at a impressive 4.4grams empty, with an additional BP capacity of 3g  sufficient for most 4" and 5" rockets. 

These canisters (with cap) are 1.05" Diameter, and 0.453" high

The canisters have a threaded hole on the underside for a standard #6-32 screw for attaching to your bulkhead.  

Each canister comes with one cap and stainless steel screw for mounting. 

These canisters are made in the USA

There are (2) ways of routing e-matches into the canisters: 

For BOTH options, remove 75% of the e-match protector so the tip of the e-match is visible, but the solder connections are covered and prevented from shorting. 

1) The easy way: Cut, drill or melt a small hole in your plastic cap. Feed the wire through the cap with the e-match on the inside. Add powder to the canister, and screw on the cap. If the wire hole was tight enough, you will not need anything additional to seal the hole. 

If you are prepping ahead of time, you can seal the area where the match goes through the hole with epoxy, silicone, or hot melt adhesive. 

2) The slightly less easy method: drill a 7-64" hole through the bottom of the charge canister where one of the small pilot holes are. You can fish your e-match wire under the canister before it is screwed to the bulkhead. Seal with silly putty, silicone, or hot melt adhesive if the wires are not a tight fit through the hole. 

This is a cleaner looking install, but takes more time and requires access to the underside of your bulkhead to remove the charge canister each flight. 

In an effort to be environmentally friendly, the caps can have a small slit cut in the center which will act as a stress concentrator, allowing the cap to tear open when the charge fires rather than ejecting the cap completely.