Yes there is. On a GR4 the probe folds out and connects to the basket. This one is of a Luftwaffe Tornado, but the red collar just down the shaft from the tip is the shear point.
On the RAF model, they usually also cover the collar with green tape, so that inspect it to see if there is any movement or weakening of the collar (so I have been informed).
KC-10FE will probably know this better than me, but I believe the GR4 can jettison the whole refuelling arm if necessary and the tanker can jettison the entire hose, though I may be mistaken on this (?) - I just told them where to go and what to do when they got there, what happens on the way I didn't really care about too much, but tanker issue were the most common cause of mission failure or abortion.