JIS hydraulic fittings is from Japanese Industrial Standard (JIS), all jis fittings adapters is for hydraulic hose assemblies by JIS B8363. sealing is by male 60 deg cone seat female swivel nut, it is very popular fittings in Japanese and Korean OEM market, such as Komatsu and Hyundai hydraulic excavator.

JIS fittings is used as hose adapters on equipment design, jis thread chart of connections as follows:
Male BSP 60° Cone JIS 8363 code C&R
Male BSP 30° Flare JIS 8363 code F (also be Komatsu fittings)
Male Metric 30° Flare JIS 8363 code MF

JIS adapter is designed with BSPP port and BSPT port, BSPP port is as per JIS B 2352 with o-ring seal used for high pressure system.BSPP Threads is the same: ISO 228-1 G, JIS B 0202

The differences between BSP hydraulic adaptors and JIS hydraulic adpater:
Stadnards difference, BSP fittings is as per BS 5200 standard;JIS fittings is as per JIS B8363 standard.
Thread length difference, JIS 60° Cone male thread end is longer than BSP end.
60° angle cone diameter difference.
The undercut area between thread and hex body.
These fittings, while very similar, are not interchangeable

Jiayuan produce JIS fittings adaptors absolutely according to JIS B 8363:2000 version, mostly export to Japan and Korea, supply to ISEKI tractor, LS tractor etc.
link:http://www.jiayuanfitting.com