Instruction: Given a question and its related document, determine if the question is answerable by analyzing the information in the document. Output yes if the document addresses the question, or no otherwise.

Input:
Question: I just purchased the Grex P635 and I'm going to be using 3/4 inch pins. What should the PSI be set at?
Document: What can i say if you need a micro pinner this is your choice! the only thing better is the 2-1/4 inch. this unit does not require an adjustment for the different length of nails that you are using. throw any size in and fire. Grex is the originator of the micro pinner and will always be the best, the rest are just followers.
Oh by the way this is my very first review ever submitted.Grex P635 23 Gauge 1-3/8-Inch Length Headless Pinner
After much research I decided on the Grex P635 for my pin nailer. I have used it extensively over the past month for a remodeling project. It pushes a 1 3/8" pin though 3/4" oak with no effort. Very solid construction, easy to load, easy to clear (only once) and counter sinks the exact amount in every material I have nailed.
I had never used a pin nailer or any other compressed air tool before I bought this product, so I didn't know what I was getting into. However, I have used the P635 to install maple moldings onto solid maple door frames. It drives 1 3/8 inch pins effortlessly through this hard wood - I had no pins that extended above the wood surface. Dab a little wood filler into the tiny hole, and it becomes almost invisible.
This nailer costs a little more than the others, but it appears to be well made, functioned perfectly right out of the box and has been a handy addition to my tool arsenal. The tool barely leaves a trace of a nail entry hole and adequately holds trim tight and secure. I am a professional remodeler and I looked at several similar products before ordering this one. I believe I made the right choice.Grex P635 23 Gauge 1-3/8-Inch Length Headless Pinner
I'd been using my brother in law's grex pinner for a big moulding job and it worked amazing. He has the one that uses up to 2" pins. I decided that I could use the more affordable one and got the 635, using up to 1 3/8. Now it seems that 1 out of 20 of the pins does not go in far enough. I oiled it and continued the job with the same problem.
I am very pleased with the Grex P635 pin nailer and although more expensive than other pin nailers, the difference is well worth it. After using other pin nailers, the Grex P635 is my choice because of the following reasons: 1) consistently countersinks pins even in heavy oak trim, no jams experienced, easy to load, has wide range of pin lengths, holding strength of Grex pins is excellent. Perhaps the only downside is the availability of Grex pins - get them when you order your nailer.
(see revision below) I wasn't led astray by others who raved about this 23 gauge pinner. It saved the day as far as doing an intricate exterior Ipe handrail with polyurethane glue. No other brad or nailer would work except my old Senco 1/2 thru 3/4 inch pinner and it leaked and didn't have the power of this new one.
I am simply amazed by this pinner. I have used many others with less features and the Grex p635 is a hands down winner. Few manufacturers offer a 23ga pinner as versatile as the P635 with the capability to shoot 3/8 to 1 3/8 pins and self adjusting to boot. No splitting of crown or delicate hardwood mouldings even within 1/8" of an end mitre. I have pretty much retired my 18ga brad nailer for high end trim in leu of the Grex P635.
I chose the GREX P635 23 Gauge 1-3/8-Inch Length Headless Pinner based on recommendations of other users and it's greater capacity for variable pin size. So far it has functioned flawlessly in various density of wood and leaves no mars or obvious nail holes. The nailer's quality is obvious when you first handle it, as compared to my  other nailers. I wish I had it when I trimmed my cabinets.
Answer: yes