These robust connectors, often referred to as Siemens type, but are available from several manufacturers, including Telegärtner and Binder.
30 pin types (DIN41622) have large easily soldered contacts arranged (with staggered centre pins) in rows of three, with row A commonly used for hot, B for cold, and C for screen. Metal locking housings are fitted to panels using connector fitting bolts, and locate with shielded (metal) cable housings, to give a positive lock. The cable housing will fit through an aperture of only 50mm x 24mm.
The 39 pin types (DIN41618) are similar to the 30 pin types, but feature a higher pin density. They use the same cable housing and panel mount trough. Contacts are silver plated.
Please note that cable connectors cannot be connected in-line.
Screws to secure connector bodies into the trough or cable housing have extended heads which are either male (ball) or female (cup). Screws must be arranged to mate and can be combined on connectors in four combinations (m+m, m+f, f+m and f+f) to ensure the correct connection of cables. Priced and sold singly.
||3 x 1mm knife blade style, gold (DIN41622) or silver (DIN41622 and DIN41618) plated
||4-point wiping spring, gold (DIN41622) or silver (DIN41622 and DIN41618) plated
||10A at 200C
For dimensional details, please see the linked resources.