The Wratten 70 gel filter is best for shooting infrared film. It passes both the longest red and the infrared wavelengths with nearly all of the remaining visible spectrum blocked (see chart- essentially everything under ~650nM is absorbed). 

This means there is a bit of visible light (wavelengths between ~650-700nM) with which you can compose and focus your shots. The major beef with "strictly" infrared filters is they pass little if any visible light (see graph), making any real photo shoot extremely problematic since your eyes can't see through infrared filters to focus and compose. What is more, the Wratten 70 passes less visible light than either the Wratten 25 or 29, giving a pure infrared rendition of the subject you are photographing. To my knowledge, this filter is not currently produced in glass. 

With B&W films, this filter will produce the effect of very light foliage, intriguing skin tones, and dramatically darkened skies. 

The filter is new and sealed in original Kodak packaging. Free domestic shipping and low cost international shipping in a hand addressed envelope. (Tracked shipping available- select the higher cost shipping option.)