It's design is pretty nice, the amount of hop is controlled by a knurled disc with a stepped, threaded shaft. The underside has been cut so it fits with a ratchet in the scope mount, making it easy to measure the amount of hop you give the weapon. As you tighten the disc the nub is pushed down.
It'd be nicer if finding parts for the M700 wasn't so annoying. The best tightbore barrels for it are supposed to be the 6.01 640mm EDGi barrels, however the only place I can find them (Evike) doesn't stock them any more; and rumour has it they've moved to a chinese factory with terrible QC. I'm gonna have to make do with MadBull 6.03mm 650mm or a LayLax 6.02 590mm tightbore.
Thankfully FireSupport stock the rest of the parts I need.
(A short list if PT247 needs it for his takedown version M700)
LayLax 6.02mm 590mm TBB w/rubber
G&G gas route connector spring
G&G Hop rubber and seal set for M700 (gonna test the difference between G&G and LayLax rubbers, plus it's all 1 product)
King Arms steel strike plate w/striker spring
All totals at £99.50 incl. delivery.
Ouch