Instruction: Answer the given question using the supporting document.

Input:
Question: what size should I purchase for a Canon EF 70-300mm f/4-5.6 IS USM Lens?
Document: This fit my Canon EF 70-300mm f/4-5.6 IS USM lens perfectly. I could not have found anything better, you wont go wrong purchasing this.
Fits the Nikon 70-300mm f/4.5-5.6 G-AFS ED-IF VR LENS like a glove, great padding and good quality. Fits much better than the Lowepro Lens Case 11 x 26 (Black) which is too big.The only issue is that there's no strap so you can't easily carry this on your person. It relies on using Tamrac's M.A.S.
Dimensions on Amazon was 4.5 x 8 inches. My ruler at home says 4 x 7 inches. Then when my Canon 70-200mm lens says it is 6.8 inches, that does not include the lens cap, UV filter and back lens cover. Sending it back.
This is the first Tamrac case I purchased and am very pleased with it. Lowepro did not make a size that I was looking for and this fit the bill. It is a snug fit, without having to force the lens. I originally purchased to mate with the Tamron 70-300mm and it fit well with lens hood reversed. I now use it to house the Canon 100mm f/2.8 II L Macro, again with hood reversed.
On the Amazon website it states, " for lenses up to 6 3/4". When I received the Tamrac MX5378 case the attached description card indicates, "for lenses up to 6 1/4". This 1/2" less length makes a Nikon 70-300mm lens fit very tight. Too tight to get the lens cap in with the lens.
This bag just barely doesn't fit my Canon 70-200mm f/4L lens. I had hoped it might, but it doesn't. However, it is a perfect fit for my 17-55mm f/2.8 lens, so I'm not really complaining.
This case was recommended when I bought 70-300 IS lens from some other site. The lens can barely fit inside the case. You have to make the lens smallest to make it fit.The construction is very good. Not heavy duty padding, but good enough and the belt attachment works well with my Tamron Velocity 5 bag. I think it'd work with other belt just as well.
I'm not a fan of big camera bags, instead preferring to use a Tamrac 5684 for my combo D7000 and 16-85 standby lens. But I needed a longer zoom for some shots, particularly sports and wildlife. So when I need to carry both lenses, I chose to get a standalone lens case that I can then throw in my backpack with all my other travel goodies. The MX5378 works perfect for my Nikkor VR 70-300 f4.5-5.6 IF-ED Lens.
I'm only writing this since neither the ad copy nor any reviews bothered to state the dimension of the case. Note to Tamrac:  in your listings, the word "large" is almost as bad as "you have to guess. "I don't own the case; I looked up the size of the Nikon 70-300, which is what other reviewers used to measure.I had to assign a number of stars, and I chose 5 because every Tamrac case I've owned has been both attractive and highly durable.
This lens case was designed for Canon and Nikon 70-300mm zoom lenses. My Nikon 70-300mm, with the lens hood in storage position, is a perfect fit in this case. And when I say perfect I mean perfect...perfect diameter and height...fits like a glove. Being a Tamrac, the case has good padding.
Answer: The large will fit, but only with the lens shade removed. If you want something to hold it with the shade attached, get the xtra large.