A 50ml Aluminium Jar - very lightweight and durable.
The containers are EPA (Epoxy Phenolic*) coated with this special resin on the inside so the Aluminium will not come in direct contact with your product and therefore there is no chance of reaction or oxidisation with your product.
Naturallythinking aluminium containers are totally reusable and recyclable and can be recycled with standard recycling facilities.
*EP: Epoxy phenolic internal coat is approved by the FDA in the US