If you need to find a new manufacturer for the germanium lens you need, there are some things you should always make sure each manufacturer offers before you order from them.
The most popular sizes -- If you are not ordering custom made germanium lens, you will want to be sure the company you buy from stocks the most popular sizes. That way, you will always be able to find the size of lenses you need.
Anti-reflection coatings -- Also be sure any germanium lens you order are also available with anti-reflection coatings. That way you do not have to find another manufacturer if you suddenly realize you need them.
Competitive prices -- Prices for lenses are always important, no matter what kind of lenses you buy. That is why you should always be sure the company you eventually choose offers competitive prices, and can beat their competitors' prices if needs be.
High-quality lenses manufactured in high-tech facilities -- You will want to be sure the germanium lenses you order are high-quality lenses that are manufactured in high-tech facilities on modern equipment.
You can find out this information by sending an email to any company you are considering and asking about the machinery they use, and the facilities their germanium lens are manufactured in.
Exceptional customer service -- One thing you will want to be absolutely sure you find is a company that offers exceptional customer service. Buying lenses of any type can be confusing, so you want to be sure the company you order from is able to walk you through the process every step of the way.
Finding a company with good customer service will also help ensure you are able to get any problems fixed should you have any.