It depends on how long your M-LOK slots are. Most measure out to about 1.26" in length, but vary from company to company. The 7" M-LOK rail should work great.
You will need a 1.5" length.
Unfortunately, we do not currently carry a picatinny rail/base that is compatible with the S&W Model 617.
The MDT Aluminum Picatinny M-LOK Rails are sold individually. So there is one rail per purchase.
The manufacturer doesn't specify the weight of the MDT Aluminum Picatinny M-LOK Rails. I recommend contacting the manufacturer in regards to this information.
The largest option for the MDT Aluminum Picatinny M-LOK Rail or any M-LOK to Picatinny rail adapters that we have currently is 21 slots.
I would suggest the 3.15 in MDT Aluminum Picatinny M-LOK Rail.
No, this is meant for the M-LOK style attachment system.
There are 11 length options, it will come with the corresponding length.
I recommend measuring the span you want to cover, and order the corresponding length.