I agree with Dave L about the MP gig bag being a tight fit. MP gig bags work great with MP guitars and guitars of similar size but the ES-335s and 325s are just too wide. I personally would buy a quality hard case for a fine guitar like the ES-335 before I trusting it to any gig bag.
I have a firefly hollow body guitar and it fits it perfectly. I'm sure it will your 335 size guitar. The interior is about 17" This is a great case for the price. I'm going to but another for my other firefly guitar. I have other gig bags but none fit these guitars. Good Luck
Very sturdy and well padded. Fit my Yamaha FG very nicely. Handle is at the balance point. Music pocket is generous. I bought a couple extra after my first purchase for guitars with too-heavy hard cases.
My Indio electric came in one of these. I liked it, so I got one for my acoustic. I was concerned that the 15 inch dimension might be too tight because my guitar is 15 inches. Turned out to be a very nice fit and well padded. Definitely recommend it for an inexpensive way to protect your instrument.
I was thrilled when the Monoprice gig bag was offered as a separate item apart from a package deal of some sort. This gig bag provides a surprisingly soft cushion to protect your guitar along with plenty of pocket capacity for music, strings, tuners, capos, picks, etc. It's a bit lightweight for transcontinental shipping but for $20.00 is an outstanding value. You would think a vinyl bag would be a bit stiff and crinkly but this one is soft enough to serve as a preferred nap spot by my persnickety cat.