Ultra smooth, round hardened steel rod top will let you effortlessly glide your chisel or other lathe tool for superior results; Upper support rod will not nick or scratch. Post on all four toolrests is 5/8" diameter (15.875mm). S-curve toolrest has 11" span with 3" long post with overall vertical length of 4". 1-1/2" radius J-curve toolrest has 8" span with 2-3/4" post and overall vertical length of 4-1/4". 2-1/2" radius toolrest has 6-1/2" span with 3" post and overall vertical length of 4-1/4". 2" radius toolrest has 6-3/4" span with 2-1/2" post and overall vertical length of 3-1/2". Reach far into the interior of bowls with ease; Use for bowl exterior, interior hollowing, deep penetration, and sharp corners.