What does this bit do?

[Ru88ell]

Zephyr's blocks have been around a bit, and I was thinking of renewing ahead of the season. That means throat and peak halyard blocks, jib and staysail blocks. However, looking at what I need I can't seem to find 'like for like' in the Barton ball bearing range. The peak and jib halyard blocks have what looks like an extension piece in them (the bit with black tape). Is it necessary, or can I connect the swivel directly to the s/steel bracket on the mast?

 

[PlankWalker]

Its a toggle allowing articulation in 2 directions, but the swivel on the block also does that.

One toggle on either the tang or the block is enough.

Plank

 

[PuffTheMagicDragon]

It looks like a home made extension to the tang that allows the block to be clear of the mast. Ten minutes work with a short length of stainless steel strap to suit. I could be wrong of course.