The lower type of sprung clamp ("Permagrip" TM or similar) was designed for lead services, and unlike a BS951 is supposed to assert a near constant force without damaging the lead sheath, and  is quite common here (Hants)The more modern equivalent is a spiral of spring steel that combines the worst attributes of an open corned beef can and a broken clock spring the so called 'constant force spring'

The essential idea of clamping the service cable with a bit of yield to avoid digging into the lead is the same.

Normally when updating the original bare imperial earth to the modern plastic covered stuff either solid green pre 1970 or green/yellow thereafter we try and get all the strands to be captive, but 5/7 isn't too bad I suppose 

The upper one looks like builders band and may not even be a DNO official connection.

However, if it survives the pull test and the Zs looks good, neither requires urgent attention, there is far worse in service.

Note that  if it fails some DNOs will tell you to convert to TT or request that you pay for a new supply cable.

M

The lower type of sprung clamp ("Permagrip" TM or similar) was designed for lead services, and unlike a BS951 is supposed to assert a near constant force without damaging the lead sheath, and  is quite common here (Hants)The more modern equivalent is a spiral of spring steel that combines the worst attributes of an open corned beef can and a broken clock spring the so called 'constant force spring'

The essential idea of clamping the service cable with a bit of yield to avoid digging into the lead is the same.

Normally when updating the original bare imperial earth to the modern plastic covered stuff either solid green pre 1970 or green/yellow thereafter we try and get all the strands to be captive, but 5/7 isn't too bad I suppose 

The upper one looks like builders band and may not even be a DNO official connection.

However, if it survives the pull test and the Zs looks good, neither requires urgent attention, there is far worse in service.

Note that  if it fails some DNOs will tell you to convert to TT or request that you pay for a new supply cable.

M

The upper one looks like builders band

It does, although I think I can see a hint of green in a few places where it's been bent - which might suggest it's tinned copper perforated strip - which might have been the sort of thing Electricity Board types might have had in the bottom of their tool boxes once upon a time.

From a current carrying point of view, the float shape (lots of surface area) and the extra holes, would actually make it rather efficient thermally - so it might be good for a bit more than its simple c.s.a. might suggest.

  - Andy.

It certainly has the tinned copper / original look. Hopefully the DNO can clarify as I think there may be more.